Biomedical subjects

R Loosli

Publications and source records attributed to R Loosli.

10 recordsLinked to original sources

PubMed1995

Epidemiology of atrazine.

Chronically exposed workers in chemical plants have revealed no increased incidence of benign or malignant disease attributable to atrazine. Some case-control studies showed a slight increase of non-Hodgkin's lymphoma (NHL) incidence while others were negative. Weighted evidence supports no causal association of malignant changes in farming populations with atrazine. Two studies on a rural population suggested an increase of ovarian tumors in exposed women. Neither statistics nor exposure data are satisfactory, however, and no other studies present supporting evidence. New studies under clearly defined conditions are desirable. Very high doses of atrazine ingested in suicidal attempts had no acute clinical effect, suggesting that atrazine is virtually innocuous to humans. Sporadic reports on suspected acute poisoning leave too many questions open to be convincing: they reflect coincidence rather than causality. The tolerance of ruminants to triazine is limited. Severe poisoning in case of accidental intake of concentrated products is to be expected. Poisoning through ingestion has been controlled with activated charcoal. Adsorption on fodder enhances tolerability of triazines. Suspected poisoning through spray-contaminated fodder requires differential diagnosis to avoid confusion with other pasture toxins, electrolyte problems, or gastrointestinal infection.

Acute Disease↗

PubMed1994

Triazines.

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Animals↗

PubMed1994

Formamidines.

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Animals↗

PubMed1994

Toxicology of monocrotophos.

Monocrotophos is a water-soluble organophosphate insecticide with high oral and moderate dermal toxicity. The toxicologically relevant mode of action is the inhibition of ChE activities. The toxicity of organophosphate metabolites of monocrotophos is comparable with the parent compound. Glycol conjugation in plant metabolism decreased the acute toxicity significantly. Dephosphorylated metabolites showed no demonstrable acute toxicity. Repeated exposure to the compound leads to initial cumulation of the single-dose effects. At moderate dose levels, the adverse effects are counteracted by an increase of tolerance through adaptation. A study in humans demonstrated no relevant ChE depression over a 30-d period at daily dose levels of up to 0.006 mg/kg. Lifetime chronic feeding studies in rodents again indicated ChE inhibition as the only specific effect. Body weight reduction was limited to high doses. No gross or microscopic specific lesions were demonstrable; especially, there was no evidence of oncogenic effects. Genotoxicity was evident in vitro, whereas comprehensive assessment of the in vivo tests indicates no toxicologically relevant mutagenic potential in mammals. This conclusion is supported by the absence of oncogenic effects in chronic feeding trials. Findings in reproduction studies were limited to secondary fetal reactions that were triggered by maternal toxicity. Acute and repeated administration studies in hens revealed no delayed (degenerative) neurotoxic potential. Monocrotophos showed no significant potentiation with 24 other ChE inhibitors. Poisoning signs after heavy doses were controlled by therapeutic doses of atropine, preferably in combination with an oxime.

Animals↗

PubMed1994

Monocrotophos--worker safety.

Monitoring data on field-worker exposure studies show that prolonged or continued use of monocrotophos in plant protection may lead to significant dermal exposure with an impact on cholinesterase activity. Although oral uptake (suicide) is more hazardous than dermal exposure (spray work), both exposure routes may be potentially fatal. On the other hand, prompt therapy is successful even after a heavy oral dose. The epidemiological review did not reveal a prominent risk scenario. Justification of monocrotophos use depends on agricultural need and appropriate safety measures. Eighteen cases of monocrotophos poisoning have been identified in the literature and from the manufacturer's case file. Seven cases were occupational, and nine resulted from suicide attempts. One case was a nonprofessional accident, and one was recorded without details. Further monocrotophos poisoning cases may be concealed in the unspecified data on poisoning among tropical farming communities. However, the fact remains, that only a small number of reliably reported poisoning cases are attributable to monocrotophos products, and the reports confirm the efficacy of basic medical attention to poisoning. This is in contrast to the high hazard classification and to the high perceived hazard of the products in question. Safetywise, monocrotophos appears to be better than its reputation. A level of safety precautions normally recommended for pesticide work is sufficient, even under large-scale professional use conditions, to utilize monocrotophos safely.

Cholinesterase Inhibitors↗

PubMed1978