COOPERATIVE EXTENSION UNIVERSITY OF CALIFORNIA
ENVIRONMENTAL TOXICOLOGY NEWSLETTER

Vol. 15 No. 1 February 1995

Table of Contents

Introduction

Having just returned from the DANR Statewide Conference, I am convinced that there are still some CE folks left in the counties in California, and that some of them actually read this newsletter! This issue marks a milestone as the beginning of the fifteenth year of publication. As part of our "internal celebration" of this event, I would again like to give the greatest credit to the person who has actually put it together each time, and every time; Sandy Ogletree, Environmental Toxicology Extension Administrative Assistant. Without her dedication to producing, printing and distributing this newsletter, it would not be "published occasionally at irregular intervals", it would be "published whimsically and rarely." Thanks Sandy!

In concluding this introduction, for those people who do not already know, I would like to announce that Dr. Robert Krieger is now serving as the Toxicology Specialist on the Riverside Campus. Bob was a tenured faculty member in the UCD Environmental Toxicology Department when I first came in 1980. He has since filled prominent positions in the CA Department of Food and Agriculture and the consulting industry. He brings a unique combination of talent and expertise to the job and I am looking forward to working with him once again.

Please enjoy this issue which contains lots of little bits of information that are definitely interesting and hopefully useful.

Hyponatremic Seizures Among Infants Fed With Commercial Bottled Drinking Water -- Wisconsin, 1993

In 1993, two infants were treated at a pediatric referral hospital in Wisconsin for hyponatremic (low blood sodium) seizures caused by water intoxication associated with bottled drinking water. This report summarizes information about these cases and a review of hospitalizations for hyponatremic seizures in this hospital during 1984-1993.

Patient 1

In October 1993, a 55-day-old infant was taken by her mother to the emergency department (ED) of a local hospital for evaluation of "eye twitching." During transport, she had onset of generalized, tonic-clonic seizures. Examination at the hospital revealed periorbital and gluteal edema; her serum sodium level was 116 mEq/L (normal: 135-145 mEq/L), and metabolic acidosis was documented by blood gas analysis. Status epilepticus secondary to hyponatremia was diagnosed.

Treatment was initiated with intravenous anticonvulsants. Forty-five minutes after onset of seizures, the infant experienced respiratory depression. Following endotracheal intubation, the infant was transported to the children's hospital, where she received intravenous normal saline. Serum sodium subsequently normalized, and metabolic acidosis resolved. The infant was discharged after 5 days and recovered fully.

The infant's mother had been buying cow's milk-based infant formula and had been supplementing feedings with several ounces of bottled water for several days. She reported using bottled water as a supplement because the product was inexpensive and because she interpreted the labeling to indicate that the product had been produced specifically for infants and contained nutrients adequate for use as a feeding supplement. The mother later reported to the Food and Drug Administration (FDA) that she had substituted tap water for infant formula during the 24 hours before hospitalization.

Patient 2

In December 1993, a 56-day-old infant was transported to the ED at the children's hospital following an apparent brief seizure. He had had mild upper-respiratory tract symptoms for several days but otherwise had been in good health.
The infant's mother had supplemented feedings of soy-based formula with bottled drinking water since the onset of symptoms of an upper-respiratory illness.

Editorial Note: Manifestations of water intoxication include altered mental status (typically irritability or somnolence), hypothermia, edema, and seizure. Symptoms are preceded by a rapid decline in serum sodium levels (to œ125 mEq/L) and result from an acute overload of solute-free water that increases total body water by 7%-8% or more. The rapid decline in serum sodium may result in cellular dysfunction (i.e., abnormal ion gradients and cellular swelling) in the central nervous system. Factors that increase the risk for water intoxication among infants (especially those aged <6 months) include immature renal function and the powerful hunger drive of early infancy.

Hyponatremic seizures among infants resulting from improper feeding practices and water intoxication were first reported in 1967. The risk for this problem may be increased among infants of parents living in poverty. This possible increased risk may be associated with a lack of resources to purchase infant formula or oral rehydration solution and a lack of knowledge about the potential dangers of feeding infants solute-free water. The risk for hyponatremia may be particularly increased among infants aged <6 months who are vomiting or have diarrhea but who are fed fluids lacking sufficient sodium. However, symptomatic hyponatremia also may occur in infants with no acute medical conditions who are fed excess solute-free water. This problem has been caused most commonly by tap water, given either as supplemental feedings or in overly diluted formula; juices, soda, and tea also have been implicated.

Bottled water products marketed specifically for infants may be mistaken by parents and other caregivers as an affordable and appropriate feeding supplement or substitute for infants. In some stores, these products are placed on shelves alongside infant formulas or oral electrolyte solutions. Product packaging may advocate the use of bottled water for mixing with baby foods or juices but also for drinking by infants. Labels also may indicate that the water contains added minerals that babies need, including calcium, magnesium, and potassium. However, the quantity of such minerals -- which are often used for flavor enhancement -- may be unspecified. These products, generally priced at less than $1 per gallon, are considerably less expensive than infant formula or juices.

Because of the reports of bottled water use associated with hyponatremia, FDA has recommended to the International Bottled Water Association that the labels of these products clearly indicate their contents and appropriate uses (e.g., rehydrating infant formula and mixing with juices) and that they should not be used in lieu of infant formula.

Physicians and other health-care providers should discourage parents from using water (either tap or bottled) as a supplement for infants aged <6 months and should advise parents that children of any age who have diarrhea or vomiting should be given oral rehydration solution instead of solute-free water. Parents, guardians, and other child-care providers should be educated about the potential hazard solute-free water poses to the health of infants if used inappropriately.

REF: Morbidity and Mortality Weekly Report (MMWR), 43(35), September 9, 1994.

Preventive Measures Proposed for Childhood Iron Poisoning

To prevent accidental, potentially fatal childhood poisonings, FDA is proposing that packages of capsules and tablets containing iron be labeled with warnings.

The proposal, published in the October 6, 1994, Federal Register, applies to prescription and nonprescription products. It would require manufacturers to enclose any product with 30 milligrams or more of iron per pill or capsule in single-dose packaging, such as blister packs. Most prenatal iron products contain 30 mg or more of iron and are likely to be in homes with young children.

Accidental ingestion of iron is the leading cause of poisoning deaths in children under 6, despite child-resistant packaging. Since 1986, over 110,000 such incidents have been reported, leading to 33 deaths.

The proposed warning would appear in a conspicuous area on all solid oral-dosage products containing elemental iron or iron salts. It would state that an iron overdose could harm or kill a child and would caution adults to:

REF: FDA Consumer, December 2, 1994.

Cost-of-Illness Method Applied to Foodborne Pathogens by Researcher

Applying a cost-of-illness (COI) method to foodborne bacteria was the subject of a Nov. 28 seminar conducted by Jean Buzby of the University of Kentucky, an agricultural economist working on a cooperative agreement with USDA's Economic Research Service, which has a new section focusing exclusively on food safety.

Buzby examined four pathogens: Salmonella, 87%-96% of which is foodborne; Campylobacter jejuni or coli, 55%-70% of which is foodborne; E. coli O157:H7, 80% of which is foodborne; and L. monocytogenes, 85%-95% of which is foodborne.

Foodborne Salmonella cases for 1993 numbered 696,000-3,840,000 and 696-3,840 deaths; foodborne Campylobacter cases numbered 1,418,494-1,805,356 and 110-511 deaths; foodborne E. coli O157:H7 cases numbered 8,000-16,000 and 160-400 deaths; and foodborne L. monocytogenes cases numbered 1,526-1,767 and 377-475 deaths, she estimated, for a total number of foodborne cases for the four pathogens of 3,390,875-6,600,940 and 1,644-5,730 deaths.

Medical costs and lost productivity for the four pathogens resulting from foodborne illness ranged from $1.73 billion to $5.3 billion, and an additional $179 million-$902 million in losses was caused by foodborne C. jejuni-induced Guillain-Barre Syndrome (GBS), Buzby said, with total foodborne losses, $1.9 billion-$6.2 billion.

The probability range for jury verdicts on food poisoning from 1989 to 1994 was $4,550-$38,000 (25th-75th percentile), Buzby said.

REF: Food Chemical News, 36(41), December 5, 1994.

Prilocaine-Induced Methemoglobinemia -- Wisconsin, 1993

Methemoglobinemia is an uncommon disorder in which hemoglobin is oxidized and not capable of binding oxygen. This condition may be associated with exposure to nitrate-contaminated drinking water, aniline dyes, and amide-containing medications. Ortho-toluidine, a metabolite of the anesthetic prilocaine, also can induce this condition. During March-August 1993, three Wisconsin women treated by the same oral surgeon developed methemoglobinemia after being injected with a prilocaine-based local anesthetic.

In Case 1 the oral surgeon had administered anesthetic of 560 mg prilocaine. A sample of venous blood was described as brown and indicated a methemoglobin level of 27%. In Case 2 the oral surgeon had administered 560 mg prilocaine and a venous blood sample revealed a methemoglobin level of 28%. In Case 3 the oral surgeon had administered 480 mg prilocaine and the methemoglobin level was 10.7%.

Editorial Note: Administration of prilocaine in doses exceeding 400 mg has been associated with methemo-globinemia in adults. Proportionately lower doses may cause this problem in children. Methemoglobin levels above 10% may result in clinical anoxia, and levels above 60% can cause stupor, coma, and death.

During January 1992-September 1993, FDA received nine reports of prilocaine-induced methemoglobinemia. However, methemoglobinemia may be underreported because 1) some persons may develop only mild symptoms that do not require medical care, 2) some cases may not be recognized as prilocaine-induced, and 3) only drug manufacturers are required by law to report these events.

Oral surgeons and other health practitioners should use accurate body weight information to calculate safe doses of prilocaine and should know that doses exceeding 4.0 mg per pound (8 mg/kg) of body weight pose a risk to healthy adults. The risk for adverse effects associated with prilocaine use is increased for infants, persons with underlying health problems (i.e., anemia or diseases affecting the respiratory or cardiovascular systems), persons with hereditary deficiencies of glucose-6-phosphate dehydrogenase and methemoglobin reductase, and persons taking other oxidant drugs (e.g., nitrite-containing medications, sulfonamides, antimalarials, or acetaminophen).

REF: MMWR, 43(35), September 9, 1994.

Type B Botulism Associated with Roasted Eggplant in Oil -- Italy, 1993

In August and October 1993, public health officials in Italy were notified of seven cases of type B botulism from two apparently unrelated outbreaks in different communities.

Outbreak 1

On August 14, two waitresses working in a sandwich bar in Santa Maria di Castellabate were admitted to a local hospital with dysphagia (inability to swallow), diplopia (double vision), and constipation; a clinical diagnosis of botulism was made. On August 12, the waitresses had prepared and eaten ham, cheese, and eggplant sandwiches. A third waitress also ate the sandwiches and developed dyspepsia for which vomiting was induced; she did not have neurologic symptoms. The owner of the bar, who had tasted a small piece of eggplant from the same jar later on August 12, remained asymptomatic. The cook had initially opened the jar of commercially prepared sliced roasted eggplant in oil and had tasted its contents on August 11 and developed diarrhea. Both the cook and the owner reported that the eggplant tasted spoiled.

Botulism was presumptively diagnosed in the two hospitalized patients; both were treated with trivalent botulism antitoxin and gradually improved. No food samples were available for testing. No botulism toxin was detected in the serum of the two hospitalized patients. However, cultures of their stools subsequently yielded type B Clostridium botulinum.

Outbreak 2

During October 5-6, four of nine members of an extended family who had dined together on October 2 were hospitalized in Naples with suspected botulism. The meal consisted of green olives, prosciutto, bean salad, green salad, mozzarella cheese, sausages, and commercially prepared roasted eggplant in oil. Based on an investigation and analysis of food histories, the eggplant was implicated as the probable source. All of the patients were treated with trivalent botulism antitoxin and gradually improved. Investigation indicated that on September 27, another family member had opened and dipped a fork into the implicated jar of eggplant; although he did not eat any eggplant, he used the fork for other food items. On September 28, he had developed vomiting, dysphagia, and double vision but was not hospitalized; his symptoms resolved spontaneously. On October 8, he was asymptomatic but was hospitalized and treated with trivalent botulism antitoxin after botulism was diagnosed in other family members.

One of the hospitalized patients developed respiratory muscle weakness and required mechanical ventilation.

Follow-Up

The commercially prepared eggplant suspected of causing both outbreaks was produced by one company and sold only in Italy. The company reported preparing the eggplant in the following manner: eggplant slices were washed and soaked overnight in a solution of water, vinegar, and salt; roasted in an oven; and subsequently placed in glass jars. Garlic, peppers, oregano, and citric acid were added. The mixtures then were covered with sunflower oil and sealed with screw-on lids; after being filled, the jars were boiled in water for 30 minutes.

Public health officials issued a national warning and recalled unused jars of eggplant. No additional cases of botulism associated with this product were reported.

REF: MMWR, 44(2), January 20, 1995.

26% of Apple Juice Samples in FY 93 Unacceptable for Export, FDA Finds

Of 101 apple juice samples tested for patulin (a mycotoxin produced by a number of molds) by Food and Drug Administration analysts in a fiscal year 1993 assignment, 26 (26%) contained levels in excess of 50 mg/L. While the U.S. has no regulatory level for patulin, "more than ten other countries" have established a level at 50 mg/L, according to FDA's summary of the results. The summary said the Center for Food Safety and Applied Nutrition has undertaken a risk assessment for patulin.

According to the summary, 101 apple juice samples were taken and grouped into four categories: juice reconstituted from concentrate; frozen concentrated juice; juice from fresh-pressed apples; and juice from pressed apples blended with juice reconstituted from concentrate.

Included among these categories was apple juice labeled as infant juice. Patulin levels for these 20 samples, ranging from <2 mg/L to 17.6 mg/L, were "generally lower than the overall levels."

Summary results revealed that these overall patulin levels ranged from <2 mg/L to 912 mg/L. Seventy-five samples contained levels from <2 mg/L to 50 mg/L; 23 samples contained levels from 51 mg/L to 500 mg/L; and three contained levels >500 mg/L.

38% of Sweet Corn Samples Contain Low Levels of Fumonisin

Of the 97 samples of frozen and canned sweet corn analyzed under the same assignment, 38% contained "low levels" of fumonisin (a mycotoxin produced by Fusarium moniliforme) (4-82 ng/g). Of 70 canned corn samples, 42 contained levels <4 ng/g; 28 contained levels ranging from four to 82 ng/g, and one sample level was reported at 235 ng/g.

Of the 27 samples of frozen corn, one had a level of 350 ng/g; 18 contained levels <4 ng/g; and nine contained levels ranging from eight to 25 ng/g.

REF: Food Chemical News, 36(43), December 19, 1994.

Methyl Mercury Violations Greater for Domestic Shark, Swordfish

A summary of fiscal year 1993 testing for levels of methyl mercury in imported and domestic shark, swordfish and tuna revealed a residue violation rate of 27.3% for domestic fish and a 6.7% rate for fish imported into the U.S.

According to the summary, 33 samples of domestic fresh/frozen shark and 25 fresh/frozen swordfish samples were analyzed. From these samples, 17 shark (51.5%) and nine swordfish (37.5%) samples were found in violation, reporting levels above 1 ppm. Twenty-five imported fresh/frozen shark and 59 swordfish samples were also analyzed, with no violations detected in the shark samples and five (13.5%) found in the swordfish.

No violations were found in either the domestic or imported samples of canned and fresh tuna. There were 15 domestic canned samples and 23 fresh samples analyzed and 18 imported canned and 30 canned samples studied.

REF: Food Chemical News, 36(43), December 19, 1994.

Carbon Monoxide Poisoning - Weld County, Colorado, 1993

In March 1993, the Colorado Department of Public Health and Environment (CDPHE) was notified that six family members residing in a home in Weld County had suffered carbon monoxide (CO) poisoning; five of the persons died. An investigation indicated that the source of CO had been a van parked in the garage of the home; the van had been left running, and the exhaust fumes leaked into the home.

On March 10, 1993, at 7:32 p.m., emergency personnel in Weld County received an inactivity alert from the heart monitor of an outpatient. On arrival at the patient's home, they found the six family members (three adults and three children) to be dead or unconscious. Four persons (a 77-year-old woman who was wearing the heart monitor, two other adults aged 29 and 30 years, and one 8-year-old child) were pronounced dead at the scene. The decedents were found on the first floor of the house, in upstairs bedrooms, and in the basement; on autopsy, carboxyhemoglobin (COHb) levels of the decedents ranged from 72% to 78%. Two other children (aged 12 and 11 years) were found unconscious in the basement. Although their initial COHb levels were similar, clinical features of the two patients were distinctly different.

Investigation. A police investigation suggested that a van parked in the garage of the family home had been left running after the family had returned from an outing the previous night, approximately 24 hours before discovery. The garage adjoined the family room on the first level of the tri-level home. When emergency personnel arrived at the home, they found the door between the garage and the house was closed.

Approximately 2 hours after discovery of the family, environmental sampling by the gas company detected CO levels ranging from 17 to 64 parts per million (ppm) throughout the house; a sample from inside the van measured 448 ppm CO.

Diagnosis of CO poisoning is problematic because early symptoms of CO exposure are nonspecific (e.g., headache, dizziness, weakness, nausea, visual disturbances, and confusion) and may be mistaken for symptoms of acute, self-limited illnesses (e.g., upper respiratory tract infection and food poisoning). At least three factors are associated with COHb levels and symptoms: 1) the concentration of CO in the environment; 2) the duration of exposure; and 3) the interval between exposure and clinical assessment (as illustrated by the cases described in this report). In general, however, exposure to CO concentrations of 80-140 ppm for 1-2 hours can result in COHb concentrations of 3%-6% (normal concentration: <2% for nonsmokers, 5%-9% for smokers); this concentration may be associated with decreased exercise tolerance and, in persons who are at risk, may precipitate angina attacks and cardiac arrhythmias. Clinical manifestations associated with CO concentrations of 105-205 ppm and COHb levels of 10%-20% include headache, nausea, and mental impairment. Manifestations associated with COHb levels of 30%-60% include more profound central nervous system effects, coma, and death. Treatment of CO poisoning requires termination of exposure and initiation of therapy with 100% oxygen; HBO (hyperbaric oxygen) therapy has been recommended for patients with neurologic or cardiac symptoms, pregnant women, and children when higher cortical function cannot be measured.

REF: MMWR, 43(42), October 28, 1994.

" TIDBITS "

Wicker Baskets Not Suitable for Food Service

In response to inquiries, FDA said the difficulty in cleaning both natural and imitation wicker baskets make them inappropriate for "serving food, either directly as a food contact surface or indirectly with a liner," according to the Food Marketing Institute.

REF: Food Chemical News, 36(42), December 12, 1994.

'Minute Quantities' of Dioxin are Ingested

Dioxin and related compounds are considered to be "probable" human carcinogens but are not "known" to be carcinogenic, so it is possible that no cancers may be attributable to dioxin and its related compounds, the Environmental Protection Agency noted. Despite the potential for adverse noncancer effects, there is currently no clear indication of increased disease in the general population attributable to dioxin-like compounds. It is in this context that the risks are considered to be 'theoretical.'

REF: Food Chemical News, 36(42), December 12, 1994.

No Adverse Reproductive Outcome from Dioxin Exposure

A study of 2,629 U.S. Air Force veterans of the Vietnam War -- 1,089 who regularly handled and sprayed dioxin-containing herbicides (Agent Orange) as part of Operation Ranch Hand in Southeast Asia from 1962-1971 and a comparison group of 1,540 who served in the same region at the same time but who were not occupationally exposed to herbicides -- showed that paternal exposure to Agent Orange and its dioxin contaminant was not associated with adverse reproductive outcomes, Air Force and Centers for Disease Control and Prevention researchers reported.

In a recent study, scientists noted that they "found no meaningful elevation in risk for spontaneous abortion or stillbirth. In analyses of birth defects, we found elevations in risk in some organ system categories, which, after review of the clinical descriptions, were found to be not biologically meaningful."

The researchers noted that there was an increased risk of spontaneous abortion of babies conceived by veterans in the background (<10 ppt) and low-dioxin <110 ppt) categories, with the highest risk ratio (1.3) in the low category. The categories were based on paternal serum dioxin levels. An increased risk of stillbirth was also observed in the babies conceived by veterans in the same two groups, the scientists said, with the relative risk in both categories being 1.8.

Calling the serum dioxin results "accurate," the researchers noted that the results were assessed up to 26 years after exposure in Vietnam. The initial dose calculation was based on a first-order decay law, they noted, saying: "The presumption of a constant dioxin half-life must be considered approximate in light of recent findings that the rate may depend on percentage of body fat. At present, there are insufficient data from which to derive an alternative decay rate model based on body fat or changes in body fat." "Of the 16 risk ratios for contrasts of anomaly rates in the low- and high-dioxin [>110 ppt] categories with referent rates, 11 indicated increased risk and five indicated decreased risk. Of the eight contrasts of anomaly rates among children of Ranch Hand at background levels with those of comparison veterans, there were fewer indications of increased risk than (of) decreased risk. Of the 12 specific birth defects and four disabilities, only two disabilities (delays in development and hyperkinetic syndrome) provided sufficient outcomes for formal analysis."

"Our findings do not eliminate the possibility that particular subgroups of anomalies that we were unable to examine (owing to small numbers) might be associated with paternal dioxin exposure, but the overall pattern is generally not supportive of large or widely expressed adverse effects."

REF: Food Chemical News, 36(43), December 19, 1994.

Homicides Among 15-19 Year Old Males -- United States, 1963-1991

In 1991, nearly half (13,122 [49%]) of the 26,513 homicide victims in the United States were males aged 15-34 years. In addition, among males in this age group, homicide accounted for 18% of all deaths and was the second leading cause of death (Table 1).

>From 1985 to 1991, the annual crude homicide rate for the United States increased 25% (from 8.4 to 10.5 per 100,000 persons). The homicide rate for persons aged 15-34 years increased 50% during this period (from 13.4 to 20.1 per 100,000), accounting for most of the overall increase.

TABLE 1. Leading causes of death for males aged 15-34 years-United States, 1991

Cause No. (%)
Unintentional injury 23,108 ( 32)
Homicide 13,122 ( 18)
Suicide 9,434 ( 13)
Human immunodeficiency virus infection 8,661 ( 12)
Cancer 3,699 ( 5)
Other 13,234 ( 19)
TOTAL 71,258 (100)

REF: MMWR, 43(40), October 14, 1994.

Warnings Issued for Supplement Containing Ephedrine, Other Alkaloids

Warning letters issued by the Food and Drug Administration to Texas and Colorado firms maintain that the "Nature's Nutrition Formula One" nutritional supplement they distributed was found to contain "ephedrine and other related alkaloids," rendering it "injurious to health."

In a letter to Mark Taylor, president, Alliance U.S.A., Richardson, Texas, FDA's Dallas District said that an analysis and label review of "Nature's Nutrition Formula One," distributed by Taylor, showed the product to contain the "added poisonous or deleterious substance." The Nov. 22 letter added that an evaluation of complaints of serious injuries, including deaths, associated with the formula's consumption revealed that the product "presents a significant or unreasonable risk of illness or injury under conditions of use recommended or suggested in the product's labeling." Taylor was told he may present "views in this matter" within 10 working days.

REF: Food Chemical News, 36(42), December 12, 1994.

Cryptosporidium

Cryptosporidium is present in 65%-87% of surface water samples tested throughout the United States. However, because current techniques to detect Cryptosporidium in water are cumbersome, costly, and insensitive, tests to detect it are not routinely performed by water utilities. During 1995, EPA plans to collect additional information about Cryptosporidium and other microorganisms in surface water used by municipal water-treatment facilities in the United States and to assess the effectiveness of water-treatment methods for removing them.

The early detection of waterborne outbreaks of cryptosporidiosis is difficult for at least four reasons: 1) many physicians are unaware that Cryptosporidium can cause watery diarrhea; 2) the symptom complex often resembles a viral syndrome; 3) clinical laboratories often do not routinely test for Cryptosporidium when a physician requests a stool examination for ova and parasites; and 4) few states include cryptosporidiosis as a reportable disease.

REF: MMWR, 43(36), September 16, 1994.

Prevalence of Self-Reported Epilepsy--U.S, 1986-1990

During 1986-1990, approximately 1.1 million persons in the United States annually reported having epilepsy. The overall prevalence of epilepsy was 4.7 cases per 1000 persons. The prevalence was lowest (3.1) for persons aged >65 years and highest (5.2) for persons aged 15-64 years. The prevalence for persons aged <15 years was 4.0. The age-adjusted prevalence was similar for women and men (5.1 and 4.2, respectively), and the age-specific pattern was consistent for both sexes. The age- and race-adjusted prevalence of epilepsy was similar among the regions of the country (4.0 in the West, 4.4 in the Northeast, 4.9 in the Midwest, and 5.0 in the South).

The age-adjusted prevalence of epilepsy was higher for blacks (6.7) than whites (4.5). Compared with whites, prevalence rates among blacks were especially higher for persons aged 35-44 years and 45-54 years. This pattern was similar for both black males and black females.

REF: MMWR, 43(44), November 11, 1994.

Cigarette Smoking Among Adults -- U.S., 1993

The annual prevalence of cigarette smoking among adults in the United States declined 40% during 1965-1990 (from 42.4% to 25.5%) but was virtually unchanged during 1990-1992.

REF: MMWR, 43(50), December 23, 1994.

Deaths Resulting from Residential Fires -- United States, 1991

Most residential fires occur during December through March -- a period of colder weather and longer darkness.

In 1991, residential fires accounted for 3683 deaths; of these, 1773 (48%) occurred during January (495), February (415), March (409), and December (454). These deaths included 711 (19%) among children aged <5 years and 898 (24%) among persons aged >70 years. In comparison with the total population, the rate for fire-related death was highest for the young and the elderly.

REF: MMWR, 43(49), December 16, 1994.

Mortality Patterns -- United States, 1992

In 1992, a total of 2,175,613 deaths were registered in the United States -- 6095 more than in 1991 and the most ever recorded in one year. Despite this increase, the overall age-adjusted death rate (504.5 per 100,000 population) was the lowest ever recorded.

For 12 of the 15 leading causes of death, the death rate decreased in 1992 from 1991 (Table 1). The age-adjusted death rate for heart disease -- the leading cause of mortality in the United States -- declined by 2.6%. The rate for atherosclerosis decreased 7.7%, the largest decline among the 15 leading causes of death. Death rates from cancer decreased 1.0%, and from stroke decreased 2.2%. In contrast, rates from human immunodeficiency virus (HIV) infection and diabetes mellitus increased 11.5% and 0.8%, respectively. The death rate from HIV infection in 1992 was the highest annual rate ever recorded; in 1992, HIV infection was the eighth leading cause of death, while in 1991, it was the ninth leading cause.

TABLE 1. Percentage Changes in Age-Adjusted Death Rates

Rank Cause of death % Change
1979 to 1992
1. Diseases of heart -27.7
2. Malignant neoplasms, including neoplasms of lymphatic and hematopoietic tissues 1.8
3. Cerebrovascular diseases -37.0
4. Chronic obstructive pulmonary diseases and allied conditions 36.3
5. Accidents and adverse effects
Motor-vehicle accidents
All other accidents and adverse effects		 -31.5
-31.9
-30.1
6. Pneumonia and influenza 13.4
7. Diabetes mellitus 21.4
8. Human immunodeficiency virus infection ---
9. Suicide -5.1
10. Homicide and legal intervention 2.9

REF: MMWR, 43(49), December 16, 1994.

Starch: A Renewable Treatment for Pesticide Clothing

Researchers have found that ordinary laundry starch on regular cotton clothing protects pesticide applicators from harmful chemicals. Starch binds with chemical pesticides and keeps them away from the skin until the clothing can be washed. It is biodegradable, inexpensive, and familiar to most consumers.

Cotton and cotton-polyester garments that have been starched provide a durable finish that traps pesticides and prevents their transfer to the skin, and allows moisture vapor to be transported away from the skin. The starch-bound chemicals are rinsed away in the wash.

Remember, however, that it is important to always wear the appropriate protective clothing when applying pesticides.

Also, always wash pesticide protective clothing separately from all other clothing.

REF: Kansas Pesticide Newsletter, 17(6), June 18, 1994, (as seen in Pesticide Quarterly, NDSU).

DEET and Anti-Nerve Gas Drug Implicated in "Gulf War Syndrome"

An experimental anti-nerve gas drug that was prescribed by the Department of Defense for 695,000 soldiers during the Persian Gulf War may have boosted the toxicity of N,N-Diethyl-m-toluamide (DEET) in the field, triggering veterans' symptoms known as Persian Gulf War Syndrome, Senate Committee staff members noted recently.

Last year, a USDA scientist who was conducting research on cockroaches found evidence that could have important implications for Persian Gulf War veterans, Senate Veterans' Affairs Committee staff members said at a May 6 committee hearing on hazards of military research. The scientist, Dr. James Moss, found that when used in combination with pyridostigmine, DEET became 10 times as toxic as when used alone.

Senate Veterans' Affairs Committee staff members investigating the use of the anti-nerve gas enhancer pyridostigmine made a connection between DEET and other insecticides used by soldiers in the field to combat sand flies and scorpions, and their possible synergistic effects with pyridostigmine.

Pyridostigmine bromide, a carbamate, is a chemical that enhances the effectiveness of established drugs for treatment of nerve gas poisoning, but only when appropriate doses are selected.

The report stated, "DEET and many other pesticides were commonly used during the Gulf War. If individuals who took pyridostigmine pills become more vulnerable to pesticides (or vice versa), this could explain the serious neurological symptoms experienced by so many Gulf War veterans."

The report went on to note that two antidotes to nerve agents, atropine and pyridine-2-aldozime methochloride (2-PAM), are enhanced if pyridostigmine has already been given. "It should be noted," the staff report said, "that 2-PAM itself may intensify the effects of carbamate poisoning, so that if a soldier had an adverse reaction to pyridostigmine [from its combination with pesticides] the use of 2-PAM could make the reaction worse."

REF: Kansas Pesticide Newsletter, 17(6), June 18, 1994, (as seen in Pesticide & Toxic Chemical News 22{28}).

General Mills Begins Disposing of Adulterated Cheerios

General Mills has informed the Food and Drug Administration's Minneapolis District in an August 2, 1994 letter that it has begun to dispose of about 55 million packages of oat-containing breakfast cereals (mainly Cheerios) through landfill and incineration methods.

The company was responding to a July 15 warning letter noting that FDA's analytical findings showed that whole grain oats stored at or distributed by General Mills contained the illegal pesticide chlorpyrifos-ethyl, and that the company subsequently processed and distributed oat products adulterated with the residues into interstate commerce, in violation of the Federal Food, Drug, and Cosmetic Act.

Additionally, the company said that approximately 25 million pounds of oat flour, oat hulls and other in-process products will be landspread, incinerated or landfilled, noting that much of this material has been denatured, or will be, and landspread as a fertilizer. As with the breakfast cereals, the company stated that "all destruction is being completed under secured and witnessed control with appropriate documentation," and all records will be made available to the agency upon request.

REF: Food Chemical News, 36(25), August 15, 1994.

Pesticide Misuse on General Mills' Oats - Update

The applicator was found guilty of illegally applying chlorpyrifos-ethyl to 19 million bushels of oats to be used in breakfast cereals. Y. George Roggy, head of Fumicon, Inc., Edina, Minn., was found guilty of 13 federal counts in a jury trial, an EPA official noted. He faces a long prison term and stiff fine. The U.S. attorney said the conviction sends a strong signal that it does not pay to tamper with our nation's food supply.

In a closely related story, it was noted that a petition for a time-limited tolerance of 15 ppm for chlorpyrifos on oat grain to be used for feed has been filed by General Mills with EPA.

REF: Kansas Pesticide Newsletter, 17(12), December 12, 1994.

Ostrich Fern Poisoning - New York and Western Canada, 1994

Fiddleheads (crosiers) of the ostrich fern (Matteuccia struthiopteris) are a seasonal delicacy harvested commercially in the northeastern United States and in coastal provinces of Canada. Although some common ferns may be poisonous or carcinogenic, this species has been considered to be nontoxic. However, in May 1994, outbreaks of food poisoning were associated with eating raw or lightly cooked fiddlehead ferns in New York and western Canada. This report summarizes the investigations of these outbreaks.

Steuben County, New York

On May 19, 1994, a restaurant in Steuben County, New York, reported to the New York State Department of Health (NYSDOH) gastrointestinal illness among a group of 20 persons who had eaten at the restaurant the preceding night. Patrons complained of nausea, vomiting, and diarrhea shortly after eating, and some attributed their illness to the fiddlehead ferns served with their entree. The restaurant received similar complaints from a group of 22 persons who ate fiddlehead ferns on May 6 but had not previously reported illness.

During May 25-28, NYSDOH conducted a telephone survey of persons who had eaten at the restaurant on days fiddlehead ferns were served (May 6, 7, and 18). A case was defined as vomiting or diarrhea within 12 hours of eating at the restaurant. Of the 56 restaurant patrons who could be contacted, 31 (55%) met the case definition. Of these, 30 (97%) reported diarrhea; 22 (71%), nausea; 10 (32%), vomiting; and eight (26%), abdominal cramps. The mean incubation period was 6.7 hours (range: 0.5-11.5 hours). Symptoms lasted a mean of 1.3 days (range: 3 hours-3 days). Cases occurred among 30 (67%) of 45 persons who ate fiddlehead ferns, compared with one of 11 persons who did not (relative risk [RR]=7.3; 95% confidence interval [CI]=1.1-48.1). The risk for illness was greater for those who ate a full order of ferns (i.e., 8-10 fiddleheads) (RR=8.8; 95% CI=1.4-57.5) than for those who ate a half order or only tasted the ferns (RR=2.2; 95% CI=0.2-20.7). No other restaurant food was associated with illness.

The ferns had been harvested from two alluvial sites in Chemung County. Both sites abutted corn fields and were approximately three miles from any industry or sewage treatment plants. The harvester delivered the ferns to the restaurant washed, dehusked, and packed in plastic food storage bags. Before being served, the ferns were removed from a refrigerator and sauteed for 2 minutes in butter, garlic, salt, and pepper. No deficiencies in food handling or storage were identified. Cultures of uncooked ferns were negative for Staphylococcus aureus and Bacillus cereus. Standard tests for nitrogen/phosphorous and organochlorine pesticides were negative for chemical contamination.

On May 17, the harvester had sold ferns to a second restaurant in the area; at this restaurant, ferns were boiled for 10 minutes before they were sauteed with butter and lemon. Of six patrons who ate ferns at this restaurant on May 18, none reported illness.

Western Canada

On May 17, 1994, three cases of gastrointestinal illness linked to meals served at a restaurant in Banff, Alberta, were reported by the Banff National Park Health Unit to the Health Protection Branch (HPB) of Health Canada . A HPB investigation confirmed illness in 17 persons who had eaten at one of eight franchises of the restaurant chain in British Columbia, Alberta, or Saskatchewan during May 10-May 16. The only food eaten by all ill persons was fiddlehead ferns. Fourteen persons had eaten ferns that had been sauteed for 2 minutes with mushrooms, onions, butter, salt, and pepper; three persons had consumed fiddlehead fern soup.

During May 23-June 2, 1994, three persons contacted the HPB complaining of nausea and diarrhea after eating fiddlehead ferns purchased at Vancouver and Victoria markets. One person became ill after eating raw fiddleheads. The other two became ill after eating ferns cooked in a microwave for 7-8 minutes on low power.

On June 10, 1994, a restaurant in British Columbia reported illness among members of three groups who had eaten at the restaurant during May 28-29, 1994. Fiddlehead ferns blanched for 2 minutes in boiling water had been served with all entrees. Of the 21 persons in these groups, illness occurred among 13 (87%) of 15 persons who ate ferns but in no persons who did not eat ferns (RR=undefined; p<0.01).

A single commercial fern harvester supplied the restaurant chain. Experienced harvesters collected 3-4-inch high ferns during May 1-May 16 on federal land in British Columbia where ferns have been collected for 14 years. The site is approximately 10 miles from any development and industry and had not been sprayed with pesticides or recently flooded. The ferns were inspected to remove debris, packed in open crates, and refrigerated until delivered to purchasers.

Cooked and uncooked samples of ferns from the restaurant and raw ferns collected by the commercial harvester in British Columbia were negative for B. cereus, S. aureus, aerobic and anaerobic spore-forming bacteria, and staphylococcal toxin. There was no evidence of acute illness in mice and rats fed raw and cooked fiddlehead ferns.

Because of concerns that the ferns might contain a heat-labile toxin, Health Canada issued a warning advising that fiddleheads be boiled for 15 minutes or steamed for 10-12 minutes before eating.

Editorial Note: The ostrich fern was a spring vegetable for American Indians of eastern North America and became part of the regular diet of settlers to New Brunswick in the late 1700s. Until recently, it was consumed primarily in the Maritime Provinces of Canada and in the northeastern United States. The ferns are available commercially either canned or frozen, but since the early 1980s, farmers' markets and supermarket chains have sold fresh ferns in season.

None of the fiddlehead ferns of eastern and central North America previously have been reported to be poisonous. Although some ferns may be carcinogenic, the ostrich fern has been considered to be safe to eat either raw or cooked. One field guide indicates that wild greens may have laxative qualities and recommends boiling them and discarding the first water.

In both outbreaks described in this report, the specific cause of illness was undetermined. Although the short incubation period suggests poisoning by a preformed toxin, there was no evidence of common bacterial toxins, such as S. aureus or B. cereus. Alternatively, the plants could have been contaminated by an undetected viral agent, although this possibility is unlikely because of the apparent short incubation period. Although the ostrich fern accumulates some heavy metals, the symptoms reported in these outbreaks were not characteristic of heavy metal poisoning, and it is unlikely that absorption of heavy metals occurred at two different sites.

Because of the short incubation period and a lack of other plausible causes, the most likely cause of illness in each of these outbreaks was an unidentified toxin. Heating and boiling may either inactivate or leach the toxin from the plant. Fresh fiddlehead ferns only recently have become widely available in restaurants. In addition, many vegetables now are lightly cooked rather than steamed or boiled. In both outbreaks, the implicated ferns were either raw or lightly cooked (sauteed, parboiled, and microwaved). In a similar outbreak in British Columbia in 1990, eating lightly cooked fiddleheads was associated with gastrointestinal illness. Although a toxin has not been identified in the fiddleheads of the ostrich fern, the findings in this report suggest it may be prudent to cook fiddleheads thoroughly (e.g., boiling for 10 minutes) before eating.

REF: MMWR, 43(37), September 23, 1994.

Leading Causes of Death, by Age and Sex - Utah, 1988-1992

Injuries (i.e., suicide, homicide, motor-vehicle crashes, and all other unintentional injuries) were the leading causes of death among young persons in Utah, particularly men. Injuries accounted for 82% of deaths among men aged 15-24 years and 45% of all deaths among men aged 25-44 years; for women in these age groups, the percentages were 70% and 30%, respectively.

Injuries were also leading causes of death for young persons nationally; however, the pattern of violent deaths was substantially different in Utah. Death rates from suicide were 25%-50% higher for Utah than nationally; deaths from most other types of injury occurred at higher rates nationally than in Utah.

Death rates for males were substantially higher than rates for females at every age. Among persons in younger age groups (i.e., <45 years), higher rates for males were attributed primarily to injuries; at older ages, higher rates were largely attributed to heart disease and cancer.

Editorial Note: The findings in this report indicate that suicide has been an important cause of death for young men in Utah. From 1988-1992, the suicide rate for young men in Utah was higher than the national rate, and suicide was relatively more important in Utah because of lower death rates from other causes in these age groups.

REF: MMWR, 43(37), September 23, 1994.

VET NOTES

Toxicosis in Feedlot Cattle

Recently, the Toxicology and Chemistry (TC) Section of the Pathobiology Laboratory assisted the Kansas State Veterinary Diagnostic Laboratory with a case associated with the deaths of more than 700 feedlot cattle. The case involved toxicity from feeding contaminated milo-based distillers dried grain (DDG) in combination with monensin. A thorough field and laboratory investigation was conducted by Drs. Mahlon Vorhies and Fred Oehme of the Kansas State Veterinary Diagnostic Laboratory. The background of the case implicated a company producing alcohol for use as a gasoline additive. Milo was being used as the base grain. Under usual procedures, the solids remaining from distillation of the alcohol were dried and sold as DDG for use as a protein supplement in animal feeds. The company also reclaimed (through distillation) alcohol from industrial waste sources. Solids from the reclamation process were normally discarded.

The contamination occurred when the industrial waste solids and the milo fermentation solids became accidentally mixed. Solids from a particular lot of waste alcohol that originated at a large pharmaceutical company contained a mixture of compounds closely related to clarithromycin (a macrolide antibiotic with activity primarily against gram-positive bacteria). Clarithromycin is chemically synthesized from erythromycin. The related compounds were present as by-products of the chemical synthesis and the normal contaminants present in erythromycin. A total of 2,300 tons of DDG were contaminated and sold to feedlots, dairies, etc. At several large feedlots, the contaminated DDG was incorporated into diets that contained monensin. The combination of clarithromycin and monensin resulted in the deaths of over 700 feeder cattle. Cattle consuming DDG without monensin in the diet were not affected. As soon as the problem was discovered, the company withdrew all suspect DDG from commerce.

Affected animals began to show signs a few days after consuming the contaminated ration. Clinical signs included anorexia, depression, respiratory distress, stilted gait, and possibly ataxia.

Necropsy lesions included pulmonary congestion and edema, cardiac necrosis, hepatic necrosis, and pale abductor muscles. Histo-pathologically, pulmonary edema was present that involved the interstitia and interlobular areas but not the edema alveoli. Necrotic changes in the liver, heart, and skeletal muscle fibers were also detected histologically. Not all animals that consumed the ration died, but many had still not returned to normal 2-3 weeks after removal of the ration.

During the course of the investigation, samples were submitted to the NVSL TC Section by the Kansas State Veterinary Diagnostic Laboratory, the U.S. Food and Drug Administration (FDA), the alcohol company, VS field personnel, and individuals/practitioners who purchased DDG. Working closely with FDA, the chemical identity of the contaminants was established. The TC Section developed a method for determining the degree of contamination based on inhibitory response compared to an authentic erythromycin standard.

This contamination has had far-reaching impact beyond the feedlot level. Even though the contaminated DDG was withdrawn immediately after the problem was recognized, questions about chemical residues and public health remained. Milk from dairies that fed suspect DDG was diverted from the market until it could be tested. Feedlot animals that consumed the contaminated DDG but were not clinically affected, were withheld from slaughter until the Food Safety and Inspection Service could determine if there were any risks. After a thorough diagnostic and research investigation, milk is again being marketed and animals are being sent to slaughter.

The circumstances of this case are unprecedented in the toxicology literature. Although the chemical identity of most of the erythromycin-like compounds has been determined, toxicity data for cattle is nonexistent. The clinical syndrome has been reproduced in two feeding trials conducted in Kansas with combinations of contaminated DDG and monensin. Determining which of the erythromycin-like compounds, or combination of compounds, is responsible will take some time.

REF: The University of Georgia Veterinary Newsletter, No. 305, December 1994.

Eight Violative Milk Samples Found In Fourth Quarter Testing

Although no violative samples were found in the Food and Drug Administration's regular milk residue compliance program, 23 residue samples, including eight violative samples, were positive among those voluntarily submitted by states, according to FDA's FY 94 Fourth Quarter National Drug Residue Milk Monitoring Program (NDRMMP) report.

FDA received 1,627 sample results of milk tested by states. Twenty-three samples were found to be positive for drugs using an initial screening test. State testing using FDA-approved test kits found 17 positive results for tetracycline, four for sulfamethazine, and two for beta-lactams. The beta-lactam samples were not considered violative, but two of the sulfamethazine and six of the tetracycline samples were.

In a summary of NDRMMP's FY 1994 efforts, FDA reported that 4,147 milk samples were gathered and then screened from states collecting samples. Of these samples, 554 of 585 (95%) scheduled were selected for additional, "hard chemical" analysis at the agency's Denver laboratory. Agency testing resulted in three trace findings of chlortetracycline; six trace and six positive findings of oxytetracycline; eleven trace findings of tetracyclines; three trace and two positive findings of sulfamethazine; and one trace finding of sulfadimethoxine. The agency also provided chloramphenicol, tetracycline and sulfonamide screening kits to states.

REF: Food Chemical News, 36(41), December 5, 1994 and 36(50, February 6, 1995.

Black and White and Read All Over

But is it Safe for Cows and People?

In the past ten years, the United States dairy industry has brought to solid waste disposal problems an innovative approach -- use of shredded newspaper as cattle bedding. Interest in newsprint bedding stems from two problems. According to Cornell researcher Tom Richard, Department of Agricultural and Biological Engineering, "Farmers have been facing shortages and price increases in traditional bedding materials, while at the same time established markets for recycled newspaper have been overwhelmed by the large volumes generated by new recycling programs."

A report from the National Solid Waste Management Association, The Future Of Newspaper Recycling, found that only a third of the newspapers collected for recycling were actually reused. Widespread adoption of old newspaper for cattle bedding and litter for other domestic animals (e.g., swine and poultry) could potentially absorb 60 percent of the New York State supply, which presently constitutes up to 5 percent of landfill volume.

Newspaper also has certain inherent advantages for dairy farmers. It is relatively inexpensive, easy to spread, and more adsorbent than conventional bedding. There is some evidence that the incidence of bovine mastitis decreases when cows are switched to newspaper-lined stalls. Newspaper is also free of the debilitating fungi and toxins associated with "moldy hay."

Because cattle may eat newsprint bedding equivalent to about two percent of their diet, scientists were concerned about the possibility of milk contamination resulting from this change in bedding. Research conducted in the 1970s on the use of newspaper to line stalls indicated potential toxic problems, but with the banning of many toxic contaminants from newspaper inks in the early 1980s, old newspapers became more attractive to dairy farmers.

A paper by Richard in early 1990, which addresses the possibility of heavy metal contamination from toxic inks, prompted other researchers to take on the extraordinarily complex task of assessing the risks and benefits associated with this new practice. ICET faculty member, Donald J. Lisk, director of the University’s Toxic Chemicals Laboratory, conducted a study in which dairy cows were fed a diet ten percent of which consisted of light reading -- the Ithaca Journal and USA Today. A second set of cows were fed newsprint pellets that contained no ink. Lisk found no significant levels of mutagenic substances in the milk of the newsprint-fed cows.

The results of the feeding studies are encouraging. However, the wide range of types and formulations of papers and inks, coupled with an absence of regulation or controls governing the composition of advertising supplements and inserts, makes it extremely difficult, if not impossible, to arrive at a definitive recommendation on the newspaper bedding issue. Little is known about the chemical composition of many colored inks or about whether dioxins are present in significant quantities.

Newspaper appears, then, to be a promising substitute for conventional bedding, but research on the chemical content of recycled newspaper and on the fate of these chemicals in the cows, their milk, and the environment still needs to be done. For this reason, Cornell toxicologists, veterinarians, animal scientists, extension agents, and administrators agreed at a May meeting to refrain from issuing any recommendations regarding the use of newsprint bedding. At that meeting a subcommittee was formed and charged with collecting available information on this practice and with identified critical research needs.

REF: ICET News, 6(3), Winter 1991

Art Craigmill
Extension Toxicologist
UC Davis