UNIVERSITY OF CALIFORNIA
ENVIRONMENTAL TOXICOLOGY NEWSLETTER
Vol. 4 No. 4 August 1984
VI. PLANTS, PESTICIDES AND OTHER TOXIC CHEMICALS
Table of Contents
II. Ethyl Alcohol
IV. Datura Poisoning
V. Poisoning from Elderberry Juice - CA
VI. Arsenic Poisoning in Hmong - MN
VII. Heat Exposure
VIII. Ducks Killed by Furadan 5G Use in Rice
This issue of the Environmental Toxicology Newsletter contains another potpourri of information on the toxicological and pharmacological effects of commonly encountered substances. If you are confused about the meaning of the words "pharmacological" and "toxicological", I will try to explain the particular nuances of these words. In general, pharmacological relates to desirable (therapeutic) effects and toxicological refers to undesirable effects. In 1967 I met the late Dr. Sam Scheidy who at that time worked for Smith, Kline and French Laboratories. He explained the difference as follows: "Toxicology is pharmacology in higher doses for longer periods of time". It was not until a few years later in graduate school that I realized that the converse is also true, that is; pharmacology is toxicology at lower doses for shorter periods of time. This is not a new idea at all, in fact over 400 years ago Paracelsus, a Renaissance physician, wrote "The right dose differentiates a poison and a remedy."
This newsletter addresses some recent studies about commonly used drugs and toxicants frequently encountered in the environment. Caffeine, ethyl alcohol and Datura alkaloids (atropine, scopolamine) are all therapeutic drugs and natural toxicants. The following reports of their actions in humans should alter your perception about them.
II. Ethyl Alcohol
Ethyl alcohol is a central nervous system (CNS) depressant which can be easily verified by overindulgence. It produces what is known as a descending depression of the central nervous system (brain and spinal cord). The term descending relates to observation that the CNS depression starts with our higher thought processes, and as the dose increases it proceeds to affect our ability to move (balance, speech, etc.). As the dose increases further, consciousness may be impaired (pass out), and more and more reflexes may be inhibited (cough, gag, etc.). Respiratory depression also occurs and is the usual cause of death in acute overdose situations. Recovery from self-induced ethyl alcohol poisoning (getting drunk) is invariably followed by an unpleasant syndrome of malaise, headache, etc. (the common hangover). None of this is new information to most readers.
The impairment of driving ability produced by alcohol has long been thought to be directly related to the concentration of alcohol in the blood. A recent report in the Journal of the American Medical Association October 7, 1983 issue presents new information that this may not be the whole story. A Swedish study reports that 22 volunteers were tested for their driving ability before consuming alcohol, and again after recovery from intoxication (during the hangover period) when there was no measurable ethanol in the blood. During the hangover period, driving performance was reduced by 20% compared to control values. The impairment also did not relate to how the person felt; that is those who felt fine were just as impaired as those who felt terrible. This is certainly something for non- teetotallers to think about.
The information on the topic above appeared in a column titled "Mark's Remarks" written by Dr. Mark Thoman in Veterinary and Human Toxicology 26(2):159, 1984.
III. Caffeine Effects on Blood Flow to the Brain
Caffeine is a central nervous system stimulant that also has diuretic effects (promotes urine formation). Freshly brewed coffee contains 70-100 milligrams of caffeine, and instant coffee contains slightly less. A report that single doses of 250-500 milligrams of caffeine given to 24 healthy volunteers caused a 20-25% reduction in blood flow in all regions of the brain within 30 minutes of ingestion. Caffeine has been used for years as a drug to treat migraine headache and hangover headache (which are partly due to increased blood flow). The significance of this recent report is that large doses of caffeine may have a detrimental effect on persons with cerebrovascular disease because there appears to be a direct relationship between blood flow through the brain and brain function. This is another tidbit to think about the next time you go to an important meeting and drink large amounts of coffee. Decaf anyone?
The information for the topic above was also obtained from an abstract in Veterinary and Human Toxicology 26(2):167, 1984, titled "Caffeine Buzz Restricts Blood Flow to Brain".
IV. Datura Poisoning from Hamburger - Canada
On October 18, 1983, after a husband and wife ate a meal of hamburger prepared at home, the husband collapsed, and the wife telephoned for an ambulance to take him to a local hospital. When the ambulance arrived, the wife also became unconscious. Examination of the home showed no carbon monoxide source. Within 24 hours, the couple regained consciousness and explained the circumstances of their illness.
In preparing the hamburger, the wife added what she thought was seasoning but later realized was seeds of Angels' Trumpets (Datura suaveolens) that had been drying above the stove for planting the next year. After removing most of the seeds from the cooked meat, the husband and wife ate one hamburger patty each. Less than 1 hour later, both began to hallucinate. Other symptoms were tachycardia (fast heart rate) and severe diarrhea. Both recovered and were discharged after 3 days of hospitalization.
MMWR, May 25, 1984/Vol. 33/No. 20
Author Comments: There are naturally occurring Datura species in California that could cause similar effects. There have been cases of human poisoning following voluntary ingestion of seeds and other plant parts for the purpose of inducing hallucinations. Fatalities are not uncommon after this type of intoxication and are not due to the plant per se, but to inappropriate behavior during the psychotomimetic episode. Subjects intoxicated by Datura often lose insight into the fact that the hallucinations are drug induced. This loss of insight into the cause of the abnormal state usually does not occur with other recreational hallucinogens like LSD, and is what makes the Datura type intoxication considerably more dangerous.
V. Poisoning from Elderberry Juice - California
On August 26, 1983, eight people with acute gastrointestinal and neurologic symptoms were flown by helicopter to a Monterey, California, hospital. Earlier that day, they had attended a gathering for 25 persons of a religious/philosophic group in a remote area of Monterey County. Within 15 minutes after drinking refreshments, 11 persons began to have nausea and vomiting. The eight persons most ill reported nausea, vomiting, abdominal cramps, and weakness. Some also complained of dizziness and numbness; one was stuporous and was hospitalized. Investigation by the Monterey County Health Department revealed that staff at the religious center had gathered local, wild elderberries 2 days before the outbreak and had prepared juice from them the next day. Bunches of berries were crushed with their leaves and branches in a stainless-steel press. Apple juice, water, and sugar were added, and the mixture was stored overnight. The drink was served the next day in a stainless- steel pot to the group of 25 persons. Severity of illness correlated with the amount of elderberry juice consumed; those who drank only tea remained well.
Editorial Note: The fresh leaves, flowers, bark, young buds, and roots contain a bitter alkaloid and also a glucoside that, under certain conditions, can produce hydrocyanic acid. The amount of acid produced is usually greatest in young leaves. There may be other toxic constituents in this plant. The root is probably the most poisonous and may be responsible for occasional pig deaths; cattle and sheep have died after eating leaves and young shoots.
Although a review of the medical literature revealed no other reports of elderberry juice poisoning in the past 20 years, there are older, anecdotal reports of poisoning in children from the related elder, S. canadensis. The religious center staff has been advised that, while elderberries may be safe to consume, particularly if cooked (uncooked berries may produce nausea), leaves and stems should not be crushed in when making juice.
MMWR, April 6, 1984/Vol. 33/No. 13
VI. Nonfatal Arsenic Poisoning in Three Hmong Patients - Minnesota
Patient 1: A 68-year-old woman. She had elevated levels of arsenic in 24-hour collections of urine on both her first and sixth day of hospitalization (3,334 ug and 1,284 ug, respectively; the normal level for this laboratory is less than 25 ug per 24-hour urine collection). She was treated with dimercaprol (BAL) intramuscularly and with oral penicillamine. The patient denied using Hmong folk remedies.
Patient 2: A 47-year-old woman. Her urine arsenic level 11 days after admission was 327 ug per 24-hour collection. Her serum arsenic was less than 0.01 ug/ml. She recovered, and all hematologic and biochemical abnormalities resolved without chelation therapy. The patient denied using folk remedies to overcome depression or any other illness.
Patient 3: A 39-year-old man. He had taken a root-type Hmong folk remedy. Ten minutes later, while awake, he became unconscious, and his wife called for help. Paramedics found his pulse to be 30 beats per minute, and his respirations were shallow and feeble. His 24-hour urine specimen contained high levels of several metals, including arsenic (1,815 ug), zinc (1,699 ug; normal is 300-600 ug), and iron (352 ug; normal is 100-300 ug). On dermatologic examination, he had hyperkeratosis (thickening of the skin) of the palms and sole consistent with arsenic poisoning. He was treated with BAL and oral penicillamine and recovered.
Editorial Note: There has been concern about possible arsenic exposure in the Hmong, since arsenic (in addition to lead and mercury) was found in some samples of Hmong folk remedies. Although only one of the three patients gave a history of using a folk remedy, that is still the likeliest source of arsenic poisoning. The use of folk remedies should be suspected in all Hmong patients - not only those with manifestations of acute or chronic illness, but also those who think they may be ill. Patients may go to great expense in seeking cures with herbal and other folk remedies.
MMWR, June 22, 1984/Vol. 33/No. 24
Author Note: Continuing reports of folk remedy toxicity problems in ethnic groups point out an area in which educational programs may improve the overall health of the community. Part of the problem relates to perception of traditional versus modern medicine, since so many patients deny the use of folk remedies when asked by modern medical personnel.
VII. Fatalities from Occupational Heat Exposure
A 24-year-old white male, who was employed at a surface coal mine, collapsed and later died after performing heavy labor in a hot environment. He began work at 6:00 a.m. and at 3:40 p.m., informed a coworker that he did not feel well. He walked about 50 yards to a shady area and collapsed. The outdoor dry bulb temperature was 39.4 C (103 F).
His rectal temperature registered 42.2 C (108 F). By the time he was transferred to the intensive care unit (ICU), his temperature exceeded 43.3 C (110 F). He was treated with an ice pack and intravenous fluids but died at 6:30 p.m. The autopsy report listed systemic hyperthermia with extreme generalized dilation of capillaries (cardiovascular shock) and cerebral edema as the immediate causes of death.
A 39-year-old black male, was employed as a furnace attendant at an aluminum foundry. He had pressed the wrong button and accidentally spilled molten aluminum on the floor. He spent about 15 minutes removing the spill and wore a silver reflective suit for protection against the radiant heat emanating from the metal. The outdoor dry bulb temperature was 28.3 C (83 F), and the worksite temperature was about 29.4 C (84 F); the estimated temperature of the molten aluminum in the furnace was 982.2 C (1,800 F).
He left the workplace without explanation. He was discovered 15 minutes later having seizures in the foundry parking lot. Paramedics transported him to a hospital at 5:40 p.m.; on arrival, his body temperature was 41.7 C (107 F). He remained comatose. He died the next day at 9:30 a.m. in cardiac arrest. Causes of death were hyperthermia, disseminated intravascular coagulation, and coronary arteriosclerosis.
The worker reportedly had been drinking heavily in the days before his death; however, at the time of hospitalization, he had no alcohol in his blood.
Editorial Note: Illness and death from environmental heat are important public health problems. This is especially true in the occupational setting when workers performing physical labor outdoors are exposed to higher-than-normal ambient temperatures and when such temperatures have an additive effect on heat generated by the jobs themselves.
Occupational heat-related conditions include heat cramps, heat exhaustion, dehydration, and skin disorders. In addition, the risk of unintentional injuries increases substantially with exposure to heat stress. An estimated six million workers in the United States may be exposed to occupational heat stress. Estimates of deaths and illnesses associated with occupational heat exposures are difficult to obtain, because worksite conditions and occupation are usually not listed on hospital records or death certificates; moreover, heatstroke may not be recognized as the primary cause of illness or death. However, for 1973-1976, annual reports from the California Department of Health Services alone show seven fatalities among 1,128 acute occupational heat-related illnesses. About 10%-15% of these patients required hospitalization, and an additional 40% were absent from work for varying periods after their illnesses; the remainder returned to work after medical treatment.
Certain preexisting conditions can render a person more susceptible to heatstroke; these include obesity, drug abuse, alcoholism, acute or chronic illnesses, fatigue, poor physical condition, overeating, use of anticholinergic and certain psychotropic drugs, lack of sleep, and lack of acclimatization.
An international panel of scientists convened by the World Health Organization recommended keeping a worker's deep body temperature at or below 38 C (100.4 F) to prevent heat illnesses. The following preventive measures were recommended: (1) acclimatizing new workers and workers returning from vacation or absence because of illness; (2) implementing a work/rest regimen matched to the severity of the workers' heat exposure; (3) scheduling hot operations for the coolest part of the day; (4) making drinking water and salt readily available to replace the water and salt lost by sweating; (5) making protective clothing available to workers as appropriate; (6) reducing environmental heat by engineering controls; (7) monitoring environmental heat at the job site; (8) performing preemployment and periodic medical examinations to define those at increased risk; and (9) instructing workers and supervisors about preventive measures and early recognition of the symptoms of heat-related disorders.
VIII. Ducks Killed by Furadan 5G Used in Rice Weevil Control
The California Department of Fish and Game investigated the deaths of three groups of ducks this spring. All the incidents occurred in or adjacent to rice fields. A good case history was available on one of them, as a PCA was involved and kept good records and took samples. We determined the circumstances were similar in all cases. Furadan 5G had been applied pre-flood for rice weevil control. Apparently, upon flooding the fields, ducks moved in to forage. They ingested the granules, mistaking them for either grit or seeds. Residues of up to 82 ppm carbofuran were detected in gizzard contents. Approximately 2 ppm would be lethal. A cooperative investigation will be conducted next spring by State, County, and industry representatives. We have not heard of a problem in California before now, and the material has been in use about 10 years. Studies in Texas on Furadan 3G resulted in mortalities of birds and other animals. Granules were applied to flooded fields 5 to 8 weeks after rice was planted. We request PCA's and other parties inform us if any problems arise next spring, so we can develop procedures to eliminate this hazard to resident ducks.
Ed Littrell, Dept. Fish and Game
Arthur L. Craigmill