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Biomedical subjects

R G Ames

Publications and source records attributed to R G Ames.

16 recordsLinked to original sources
PubMed1991

Investigation of a fatality among parathion applicators in California.

Staff of the California Department of Health Services investigated the death of a parathion applicator in California that was thought to be pesticide-related. A crew of eleven workers (including six sprayers, three mixer/loaders, one mixer/sprayer and one foreman) had been applying 0.125% parathion spray to almond orchards for approximately three weeks. On the day of the fatality, a sprayer rapidly developed symptoms of salivation, sweating, and convulsions after a half-day of work. Despite aggressive medical treatment, the worker died within one hour of his initial symptoms. Significant laboratory results for the decreased case included: parathion residue on the inner and outer garments worn by the worker, parathion in the post-mortem gastric contents, and elevated urinary metabolites consistent with acute parathion intoxication. Interviews with the work crew revealed that three of the 10 workers had complaints of headaches, vomiting, and/or sore throat; yet, subsequent plasma and red cell cholinesterase tests of the co-workers did not show any significant depressions in comparison with pre-season baseline values. This worker death is consistent with prior reports of parathion-related sprayer/applicator intoxications and is the first worker-related parathion death in California since 1972. Substitution of pesticides with less toxic active ingredients or the elimination of parathion is recommended.

Adult↗
PubMed1991

Multiple-episode conjunctivitis outbreak among workers at a nut-processing facility.

Workers in a Kern County almond and pistachio nut-packing facility sought medical care for eye irritation (conjunctivitis) on three separate occasions in 1987 and 1988. These incidents were investigated by the California Department of Health Services to identify the agent responsible for the eye irritation outbreak and to suggest possible remediation. The eye irritation incidents involved only the 30 to 35 workers in the preprocessor shed. Each of the three eye irritation incidents followed phosphine (Gastoxin) fumigation. Four plausible hypotheses were tested as explanations of the outbreaks of eye irritation: phosphine gas exposure, ammonia gas exposure, aluminum hydroxide dust exposure, and almond cleaning and hulling dust exposure, with or without contamination by propargite residues (Omite 6-E). None of these hypotheses received enough consistent support to be viewed as a probable cause for the illness outbreaks.

Adult↗
PubMed1989

Cholinesterase activity depression among California agricultural pesticide applicators.

Cholinesterase activity measurements for 542 California agricultural pesticide applicators under medical supervision during the first 9 months of 1985 were analyzed. Twenty-six workers, 4.8% of the sample, had cholinesterase values at or below the California threshold values for removal from continued exposure to cholinesterase-inhibiting pesticides (60% of baseline for red blood cell cholinesterase and 50% of baseline for plasma cholinesterase activity). Eight of these 26 workers, 31.5%, had pesticide-related illnesses. Pesticides most frequently associated with cholinesterase depressions exceeding California threshold values included mevinphos (Phosdrin), oxydemeton methyl (Metasystox-R), methomyl (Lannate), and acephate (Orthene); these pesticides included organophosphates in toxicity categories I and II and one carbamate in toxicity category I.

Agricultural Workers' Diseases↗
PubMed1989

Health symptoms and occupational exposure to flea control products among California pet handlers.

A statewide telephone survey of health symptoms associated with occupational exposure to flea control products among California pet handlers was conducted in 1987 following several reports of ill workers. The 696 employees interviewed worked at veterinary clinics, pet stores, pet boarding kennels, pet grooming shops, and animal control facilities. Symptom incidence and frequency and flea control product use were reported for the 3 months prior to interview. Eye and skin symptoms and unusual tiredness were elevated among workers who applied flea control products to animals or facilities. After adjustment for potential confounders, these symptoms were elevated 64% to 258% among applicators as compared to nonapplicators who worked in the same facilities. Workers who used protective clothing and equipment and followed some protective work practices were not at increased symptom risk. Some specific flea control active ingredients and application procedures were associated with respiratory effects and with symptoms suggesting systemic pesticide poisoning.

Animals↗
PubMed1989

Protecting agricultural applicators from over-exposure to cholinesterase-inhibiting pesticides: perspectives from the California programme.

California's requirement for medical supervision of applicators regularly handling Toxicity Category I and II organophosphate and carbamate cholinesterase-inhibiting pesticides is examined from a policy perspective by the California Department of Health Services (CDHS). Changes to increase the effectiveness of medical supervision and solutions to a number of practical implementation problems are discussed, including the pesticides which should be monitored, the use of individual cholinesterase baselines, the enzymes to be measured, and the frequency of cholinesterase testing.

Agricultural Workers' Diseases↗
PubMed1987

Respiratory health as a predictor of questionnaire return in a sample of United States underground coalminers.

A logistic model was used to analyse questionnaire return in a postal survey of 311 coalminers who had left their place of employment between 1977 and 1982. Three measures of respiratory health, obstruction, restriction, and presence of chronic bronchitis symptoms, were included in the model as predictors together with the possibly confounding factors of age, education, and marital and smoking status. Age was positively associated with questionnaire return (p less than 0.001). Speed of return, and whether the return was in response to a prompt, were not predicted by either the respiratory health measures or any of the other possibly confounding variables.

Adult↗
PubMed1987

Outbreak of Omite-CR-induced dermatitis among orange pickers in Tulare County, California.

An outbreak of dermatitis cases among 198 orange pickers employed by a Tulare County, California, packinghouse was investigated. Dermatitis was contracted by 114 (58%) of the 198 workers exposed when Omite-CR-treated fields were harvested. The dermatitis occurred predominantly in the exposed areas of the neck and chest. A dose-response association with dermatitis was suggested for Omite-CR exposure, but not for Carzol, Omite-CR + Carzol, or other pesticides. Because no violations of pesticide preharvest intervals or application rates were found, it appears that residue degradation was not given adequate consideration in the registration of Omite-CR, thus compromising the safety of the worker.

Agricultural Workers' Diseases↗
PubMed1985

Respiratory predictors of disability days: a five year prospective study of U.S. coal miners.

A 5-year prospective analysis tests the hypothesis that coal miners who have impaired respiratory health also experience greater numbers of disability days due to occupational injury. Occupational and respiratory health information collected for the period 1977 through 1981 by the National Institute for Occupational Safety and Health (NIOSH) on 1,118 U.S. underground coal miners was linked to coal miner injury records collected under a mandatory reporting system by the Mine Safety and Health Administration (MSHA). Respiratory impairment, based on spirometric measures, and a questionnaire measure of chronic bronchitis symptoms, after adjustment for cigarette smoking and total years of underground mining, did not provide statistically significant prediction of average disability days. In addition, respiratory impairment did not predict the number of episodes of occupational injuries resulting in days lost from work.

Absenteeism↗
PubMedDate not supplied

Effect of chlorine dioxide water disinfection on hematologic and serum parameters of renal dialysis patients.

A study of the blood chemistry parameters of 20 renal dialysis patients was undertaken when a local water district introduced chlorine dioxide (CIO2) as a disinfectant at the filtration plant headworks for 12 months without informing the renal dialysis clinic in the area of this potentially adverse change. Due to data limitations, including changes in clinical laboratories and lack of pre-exposure data for some patients, the analysis was focused on 17 patients for whom data was produced by the same clinical laboratory, for 3 months of pre-exposure and 1 month of exposure. Least-squares means of each parameter by CIO2 levels of 0.0 and 1.0 mg/L at the treatment plant were adjusted for age, sex, and creatinine. Water purification at the clinic included passing the water through granular activated carbon, filtration by 5-mu filters, and the use of reverse osmosis. Chlorination products measured at the clinic after this purification and prior to preparation of the dialysate consisted only of chlorite at the 0.02-0.08 mg/L level. No evidence of CIO2-induced anemia was found, nor were any other biologically significant responses observed. Study limitations include several potentially important hematologic parameters which were not measured, the small sample size, and three clinical laboratory changes.

Blood↗
PubMedDate not supplied

Occupational illnesses from cholinesterase-inhibiting pesticides among agricultural applicators in California, 1982-1985.

California pesticide illness investigation reports involving toxicity category I or II organophosphate and carbamate pesticide exposures among agricultural pesticide applicators were reviewed for the years 1982-1985. The pesticides associated with each illness were recorded, and the exposures were classified as chronic, short-term, or accidental. Illnesses were associated with a range of pesticides, including both organophosphates and carbamates in both toxicity categories I and II. Approximately 19% of the illnesses were due to accidents. Overall, the analysis identified a need for improving occupational health surveillance and the regulations governing worker health and safety.

Accidents, Occupational↗
PubMedDate not supplied

Acute health effects of community exposure to cotton defoliants.

In September and October of 1987, the California Department of Health Services responded to community complaints by investigating the relationship between health symptoms and community exposure to cotton defoliants. Symptoms experienced during the 1987 cotton defoliation season by 232 residents of cotton-growing communities were compared with symptoms of 175 residents of non-cotton-growing agricultural communities. Fatigue, eye irritation, rhinitis, throat irritation, nausea, and diarrhea were statistically elevated in rates adjusted for age, sex, and race and were reported 60-100% more frequently by respondents living or working near sprayed cotton fields than by the comparison group. These symptom rate elevations were substantially unchanged even after adjustment by a model of potentially confounding factors that included cigarette smoking, chronic illness, and some additional demographic variables.

Defoliants, Chemical↗
PubMedDate not supplied

Acute health effects from community exposure to N-propyl mercaptan from an ethoprop (Mocap)-treated potato field in Siskiyou County, California.

A 145-acre potato field adjacent to Dorris, California, was treated with ethoprop (Mocap) to control nematodes. Ethoprop releases n-propyl mercaptan, a highly odorous and volatile gas, as a degradation product of the pesticide. An epidemiological investigation was undertaken by the California Department of Health Services because community residents sought medical attention for odor-related illness. Elevated health effects were found among those who reported smelling a strong odor (n-propyl mercaptan has a characteristic onion-like odor). In a logistic regression analysis, the most highly elevated 6-wk health effect incidence risks, expressed as odds ratios (ORs) adjusted for age, sex, and current cigarette smoking status, were for headache (OR = 5.08), diarrhea (OR = 3.80), runny nose (OR = 5.31), sore throat (OR = 3.58), burning/itching eyes (OR = 5.64), fever (OR = 3.59), hay fever attacks (OR = 3.50), and asthma attacks (OR = 6.0). Based upon these elevated health effects, it is recommended that human exposures to n-propyl mercaptan be minimized to the extent practicable.

Adult↗
PubMedDate not supplied

Respiratory disease and suicide among U.S. coal miners: is there a relationship?

A case-control study was performed to test whether or not respiratory disease in coal miners presented a risk for suicide. While coal miners in general do not experience elevated rates of suicide, coal miners with respiratory disease have been found to have high rates of psychiatric disability, especially depressive reactions. Further, depression has been related to suicide. To test the hypothesis, 50 suicide deaths from four National Institute for Occupational Safety and Health cohorts of coal miners were matched by age at death to two series of controls, a noncancer, nonaccident control series, and a cancer control series. Using odds ratios (tested by chi-square) the risks of obstructive lung disease and coal workers pneumoconiosis were evaluated together with the risks of years of underground mining, cigarette smoking at the time of cohort creation, and ever having smoked cigarettes. Neither respiratory disease was found to pose a statistically elevated risk of suicide in this sample of U.S. white male coal miners.

Adult↗