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Biomedical subjects

P Monge

Publications and source records attributed to P Monge.

9 recordsLinked to original sources
PubMed2001

Chronic nervous-system effects of long-term occupational exposure to DDT.

Dichlorodiphenyltrichloroethane (DDT) is a compound with moderate toxicity that is judged to be safe for occupational use, although little is known about its long-term effects on the human nervous system. We investigated chronic nervous-system effects of long-term occupational exposure to DDT by comparing the neurobehavioural performance of retired malaria-control workers with a reference group of retired guards and drivers. DDT-exposed workers did worse on tests assessing various neurobehavioural functions than controls; performance significantly deteriorated with increasing years of DDT application. Our results could not be explained by exposure to cholinesterase-inhibiting pesticides or other potential confounding factors.

Aged↗
PubMed1984

Dihydrochalcone metabolism in the rat: phloretin.

The metabolism of phloretin (2',4',6',4-tetrahydroxydihydrochalcone) was studied in rats. Approx. half of the intragastric dose (0.75 mmol/kg) was excreted in the urine, mainly within two days. Small initial amounts of phloretin were found, however most of the metabolites were degradation products. The latter included phloroglucinol and, in larger amounts, phloretic acid and related metabolites formed by its dehydrogenation, beta-oxidation and glycine conjugation. Phloroglucinol, administered in similar experiments, was rapidly (90% within 24 h) excreted in the urine, either unchanged or as conjugates (glucuronide/sulphate). Incubation of phloretin and its glucoside phloridzin with rat-caecal micro-organisms resulted in the formation of phloroglucinol and phloretic acid. The degradative pathways of metabolism of dihydrochalcones and other flavonoids are discussed.

Animals↗
PubMed1983

p-Cymene metabolism in rats and guinea-pigs.

The metabolism of p-cymene was studied in rats and guinea-pigs. Following intragastric or inhalation dosage (100 mg/kg) urinary metabolite excretion was nearly complete within 48 h, amounting to 60-80% dose. The inhalation experiments gave the lowest values. 18 urinary metabolites were detected and identified. Of these, rats did not excrete two and guinea-pigs did not excrete a third. No ring-hydroxylation of p-cymene was detected in rats, but guinea-pigs formed small amounts of carvacrol and hydroxycarvacrol. Oxidation of both the methyl and isopropyl groups of p-cymene occurred extensively in both species. The following types of metabolites were formed: monohydric alcohols, diols, mono- and di-carboxylic acids and hydroxyacids. Conjugation with glycine of the cumic acid formed was extensive in guinea-pigs.

Animals↗
PubMed1976

The metabolism of zingerone, a pungent principle of ginger.

1. The metabolism of 4-(4-hydroxy-3-methoxyphenyl)butan-2-one (zingerone), a pungent principle of ginger, has been investigated in rats. 2. Oral or intraperitoneal dosage (100mg/kg) of zingerone resulted in the urinary excretion of most metabolites within 24 h, mainly as glucuronide and/or sulphate conjugates. While zingerone itself accounted for roughly 50-55% of the dose, reduction to the corresponding carbinol (11-13%) also occurred. Side chain oxidation took place at all three available sites and oxidation at the 3-position, giving rise to C6-C2 metabolites, predominated. About 95-97% of the dose was accounted for. 3. Appreciable (40% in 12 h) biliary excretion occurred. Biliary studies and studies in vitro using caecal micro-organisms indicated that several O-demethylated metabolites found in the urine are of bacterial origin.

Animals↗
PubMedDate not supplied

Paraquat in developing countries.

The herbicide paraquat is considered safe by industry and the bulk of regulators worldwide. However, determinants of exposure from 30 years ago persist in developing countries. Little is known about systemic absorption from occupational exposures. The relationships between exposure determinants, levels of external exposure, biomarkers of exposure, and outcomes are not clear. High rates of severe acute poisonings have been documented. In addition, topical injuries occur in as many as 50% of exposed workers. Non-worker populations are also at risk, particularly children. Long-term and delayed health effects include Parkinson's disease, lung effects, and skin cancer. Regulatory agencies have not fully recognized either the inherent toxicity of paraquat or the particular risks derived from exposures in developing countries. Independent risk assessment in the developing-country context and application of the precautionary principle are necessary to prevent adverse effects of dangerous pesticides in susceptible populations.

Animals↗
PubMedDate not supplied

Hazardous pesticides in Central America.

Pesticides are an extensively documented occupational and environmental hazard in Central America. Yet, severe problems persist. Toxic pesticide use in the Region increased during 1985-1999. High exposure levels and ineffectiveness of personal protective equipment evidence the difficulties for risk reduction. Acute poisonings remain a severe problem. Delayed and/or long-lasting health effects include dermatoses, cancer, and genotoxic, neurotoxic, and respiratory effects. The use of hazardous pesticides persists through deficiencies in government-driven assessment and risk management; excessive focus on regional harmonization; short-term economic interests; strong links between industry and governments; aggressive marketing; weak trade unions; and failure of universities to reach decision makers. Regulation based on local data is lacking. An agreement of the Ministries of Health for restricting the most toxic pesticides in Central America has potential for progress. The most effective way to reduce risk is to greatly reduce pesticide use. Actions needed include development of multidisciplinary strategies for local studies on health and environmental impact of pesticides; development of sustainable nonchemical agricultural technologies; evaluation of interventions; extending and sharing of expertise within the Region; strengthening of unions and communities; and redefining the role of industry toward development of safer products, with responsible marketing and reliable information.

Academies and Institutes↗
PubMedDate not supplied

Pesticide-related illness and injuries among banana workers in Costa Rica: a comparison between 1993 and 1996.

An intervention program considerably decreased systemic poisonings on banana plantations in Costa Rica in the early 1990s. Nevertheless, pesticide safety continues to be controversial. To examine the determinants of acute pesticide-related illness on banana plantations, the authors surveyed occupational injuries and illness among banana workers in the Atlantic Region of Costa Rica that were reported during 1993 and 1996 to the National Insurance Institute. Incidence rates were calculated for categories of pesticides and types of medical problems, for all and subgroups of banana workers. Between 1993 and 1996, an overall 35% decrease in injuries was observed, attributable to a marked decline in topical injuries (3.3 vs 1.9 per 100 workers), whereas systemic poisonings remained the same (0.7 per 100 in both years). The decrease concerned selectively milder skin conditions, indicating underreporting of less severe health effects. In both years, paraquat was the pesticide most frequently associated with injuries, mostly skin and eye lesions. Workers at highest risk per unit time of exposure were nematocide applicators, herbicide applicators, and cleaners of packing plants. Despite control measures, further reduction of systemic illness had not been achieved. The decrease of topical injuries may be partly explained by improved work conditions, but possible underreporting hinders interpretation. Pesticide-related illness on banana plantations is a persistent problem.

Accidents, Occupational↗