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Biomedical subjects

O Lloyd

Publications and source records attributed to O Lloyd.

10 recordsLinked to original sources
PubMed2002

The health of the workers in a rapidly developing country: effects of occupational exposure to noise and heat.

Occupational hygiene and safety have not been high on the agenda of industrial management in developing countries for a variety of reasons. This cross-sectional study was undertaken to assess the exposure to noise and heat, and to study the level of occupational hygiene practiced, at a foundry in a rapidly developing country (Dubai, United Arab Emirates). Audiometry, muscle cramps and visual acuity were measured in workers at a foundry and compared with the results from workers at a soft-drink bottling plant. Thermal stress, relative humidity, ventilation, illumination and noise levels were measured at different work units at the foundry and at the soft-drink bottling factory. Thermal stress index was high while relative humidity and ventilation were low at the foundry compared with the bottling plant. Noise levels were also high at the foundry, exceeding 90 dB at almost all work units except the fabrication workshop. Mild or moderate visual defects were observed among 31% of foundry workers, compared with 19% of the bottling plant workers.Muscle cramps were reported by 30% of all workers at the foundry, compared with 5% at the bottling plant. Visual disability was the highest among furnace operators and fabricators. Mean hearing disability was 8.69 +/- 1.08% among foundry workers, compared with 4.56 +/- 0.82% among bottling plant workers. The high thermal stress, noise levels and exposure to non-ionizing radiations at the foundry might have contributed to the higher frequency of muscle cramps and the greater hearing and visual disabilities, respectively, among these workers. Non-use of personal protective equipment and poor occupational hygiene and safety measures were also seen to affect eye and ear health adversely among the workers at the foundry.

Cross-Sectional Studies↗
PubMed1999

Hepatic injury and disturbed amino acid metabolism in mice following prolonged exposure to organophosphorus pesticides.

Chronic occupational exposure to organophosphorus and carbamate-type pesticides significantly inhibits acetylcholinesterase activity and causes morbidity. This study on mice was designed to evaluate their amino profile and to identify signs of hepatic dysfunction following their chronic exposure to mixtures of organophosphorus pesticides. Laboratory mice were exposed to a formulated mixture of the six organophosphorus pesticides (Dimethoate, Chlorpyrifos, Profenofos, Pirimiphos methyl, Triazophos and Dimethoate) most commonly used in agriculture in this region of the Middle East. Doses (10% of LD50 of the mixture) were given once a week by gavage in corn oil for 7 weeks; the control group was given only corn oil. At the end of the exposure period, mice were culled and blood samples were collected to determine erythrocyte acetylcholinesterase activity, biochemical markers of liver function and concentrations of serum amino acids. Erythrocyte acetylcholinesterase activity and total serum proteins decreased significantly in the exposed group. Serum concentrations of alanine aminotransferase and aspartate aminotransferase, alanine, glutamic acid, glycine, isoleucine, leucine, methionine, ornithine, proline, serine, threonine and valine were significantly increased in the exposed mice, while serum levels of cystine were decreased significantly. There were also non-significant increases in serum alkaline phosphatase, gama-glutamyl transpeptidase and some of the other amino acids. Chronic exposure to mixtures of organophosphorus pesticides is associated with decreased acetylcholinesterase activity, hepatic dysfunction and disturbance of amino acids profile. Biochemical indices of hepatocellular injury and disturbed amino acid metabolism may be of value as markers of chronic exposure to such pesticides.

Acetylcholinesterase↗
PubMed1998

Morbidity among farm workers in a desert country in relation to long-term exposure to pesticides.

OBJECTIVES: Farm workers chronically exposed to low levels of pesticides seldom show signs and symptoms of clinical significance. This study investigates subclinical morbidity patterns among male farm workers in a desert country. METHODS: Migrant-established farm workers (N=226) were compared with referents (N=226) and with new farm workers (N=92) who had just entered the country to work on farms. Acetylcholinesterase activity was measured, the aiming test and digit symbol test were applied, and a morbidity profile was collected with a questionnaire. RESULTS: The erythrocyte acetylcholinesterase activity and hemoglobin-adjusted erythrocyte acetylcholinesterase activity were significantly depleted in the established farm workers. The results of the aiming and digit symbol tests were also significantly lower for the established farm workers. For the morbidity profile, irritated conjunctiva (47.3%), watery eyes (52.2%), blurred vision (63.3%), dizziness (55.2%), headache (63.7%), muscular pain (61.1%), and weakness (76.6%) were reported by established farm workers in statistically significantly higher numbers than by the referents and new farm workers. CONCLUSIONS: Morbidity patterns, such as the health complaints and objective parameters suggested in this study, would be suitable as criteria for identifying farm workers most at risk from pesticide toxicity and as criteria for initiating measures to control and reduce exposure.

Acetylcholinesterase↗
PubMed1997

Erythrocyte cholinesterase activity levels in desert farm workers.

In this study we have examined 532 migrant farm workers engaged mainly in the cultivation of vegetable crops, in both greenhouses and openfarms, and an equal number of controls. Erythrocyte acetylcholinesterase activity (AChE) was measured to determine the degree of toxicity due to exposure to organophosphate and carbamate pesticides in the farm workers employed either as foremen (41.5%) or farmers (58.5%). The mean ages of the farm workers and controls were 35.2 +/- 7.4 (mean +/- SD) years and 34.6 +/- 7.1 years. AChE activity of the farm workers and controls was 3.89 +/- 0.64 UI/ml (mean +/- SD) and 4.15 +/- 0.29 UI/ml. The haemoglobin adjusted erythrocyte cholinesterase activity (HAChE) was 29.96 +/- 4.14 (mean +/- SD) for farm workers and 32.10 +/- 2.26 for controls. AChE activity was very highly significantly lower for the foremen (3.76 +/- 0.69) compared to farmers (3.98 +/- 0.59) (Student's t-test = 4.13, p = 0.0001). HAChE was also very highly significantly lower for foremen (29.24 +/- 4.37) compared to farmers (30.46 +/- 3.88) (Student's t-test = 3.64, p = 0.0001). The poorly controlled used of pesticides in the farms appeared to have caused sub-clinical intoxication in the farm workers and indicated the need for training and implementation of hygiene practices.

Adult↗
PubMed1991

Trends in lung cancer mortality in Scotland and their relation to cigarette smoking and social class.

This paper describes the trends in lung cancer rates in Scottish men and women during 1959-85, the relationship between lung cancer and cigarette consumption, and between lung cancer and social class, and the urban-rural gradient of lung cancer. Lung cancer rates in Scottish men have declined in all age groups under the age of 74 for at least the past two decades; the most notable decrease was in men aged 40-44 years, whose rates halved between 1970 and 1980. In women, who began smoking in large numbers only after World War II, lung cancer mortality declined slightly in those between 40-54 years and rose in those over 54 years. Trends in cigarette consumption did not fully explain the decline in lung cancer. Marked urban-rural gradients in the SMRs for lung cancer were evident in all periods, and these strengthened over time. Correlations between lung cancer and social class differed markedly from those found in previous studies, except for those with social classes II and V.

Adult↗