Clinical, biochemical and neurobehavioural studies of workers engaged in the manufacture of quinalphos.

59 workers exposed to different chemicals during the manufacture of quinalphos, an organophosphate pesticide (OP) and 17 control subjects were studied. Despite similar blood acetylcholinestarase (AChE) levels in both the exposed and control subjects, a significant number of exposed subjects had altered plantar and ankle reflexes. Higher nervous functions such as memory, learning and vigilance were also found to be affected in these subjects. These findings were attributed to chronic low dose combined exposure to different chemicals used/formed in the manufacture of quinalphos. The study raises the doubt that monitoring of AChE alone among subjects engaged in the manufacture of OP pesticides may not be an adequate safeguard as regards to their health.

Effect of linear alkylbenzene sulphonate on topical absorption of chromium and nickel.

The effect of the topical applications of linear alkylbenzene sulphonate (LAS), or chromium (Cr) + nickel (Ni), or the combination of LAS + Cr + Ni for 30 d were investigated. Increased activities of aspartate amino transferase, alanine amino transferase, acid phosphatase and gamma glutamyl transpeptidase and decreased activity of superoxide dismutase occurred. Increased lipid peroxidation and decreased glutathione were observed. Accumulation of Cr and Ni increased in tissues. Biochemical alterations and metal accumulations were more marked in the Cr + Ni + LAS group.

Lung function norms in healthy working women.

Two hundred seventy four healthy working women subjects representing different states were subjected to pulmonary function testing to establish linear multiple regression model. Lung functions were considered as dependent variables while age, height and weight as independent variables. Highly significant negative correlation of all lung function parameters with age and positive correlations with height and weight were observed. Females showed a decline of 0.203, 0.199 and 0.210 litres per decade in FVC, FEV0.75 and FEV1.0 parameters respectively. An increase in FVC, FEV0.75 and FEV1.0 values was found to be 0.0217, 0.0132 and 0.0178 litres respectively per unit centimeter increase in height.

Hair selenium as a monitoring tool for occupational exposures in relation to clinical profile.

Nineteen workers exposed to low levels of selenium (0.047-0.202 mg/m3 air) along with 15 control subjects were studied for clinical, hematological, radiological, and neurobehavioral variables in relation to selenium concentration in hair. The levels of selenium in the hair of exposed subjects (1.44 +/- 0.37 micrograms/g) were significantly higher than those of control subjects (0.78 +/- 0.18 microgram/g). The levels of selenium in the hair of 22 nonvegetarian subjects were found to be significantly higher as compared to 12 vegetarian subjects. Complaints of weakness and/or fatigue were found to be more prevalent in the exposed subjects. The study holds promise that hair selenium may be used as a monitoring tool for low-level occupational exposure to selenium.

Socio-economic, environmental and health aspects of farm workers engaged in mango plantations.

A cross-sectional survey of 489 male subjects in the age group 15 to 65 years engaged directly or indirectly in mango cultivation along with 208 control subjects was carried out to find their socio-economic, environmental and health conditions. The conditions like high illiteracy rate (49.5%), poverty (PCI less than Rs 100 per month, 52.2%), poor housing (mud houses, 66.7%) unsafe water supply (78.6%) were prevailing in the surveyed population. The high respiratory morbidity may be attributed to high prevalence of smoking and prolonged inhalation of organic dusts during farming operation associated with illiteracy and poor socio-economic status. Gastrointestinal disorders were related to poor hygienic conditions, smoking and consumption of contaminated water. The symptoms pertaining to CNS, skin and eyes were found to be associated with exposure to pesticides.

Generalized hair loss and selenium exposure.

The manufacture and maintenance of drums used in photocopy machines involves use of a selenium alloy. A worker employed in this type of job for 6 mo presented with alopecia aereta which later deteriorated to alopecia universalis. As selenium intoxication is known to present with a similar clinical picture, selenium levels in blood and nails of this subject were estimated and compared with those found in other workers. We report a case of alopecia universalis due to occupational selenium intoxication.

Chronic effects of hexachlorocyclohexane exposure: clinical, hematologic and electrocardiographic studies.

Twenty-six farm workers handling about 4 kg of commercial grade hexachlorocyclohexane (HCH)/y for 2-5 y and 21 control subjects were studied for chronic effects in clinical, hematological and cardiac variables. No clinically apparent morbidity was detected, but changes in hemoglobin and electrocardiograms were early effects of HCH exposure.

Organochlorine pesticide exposure and thyroid function: a study in human subjects.

We examined the serum levels of thyroxine and thyroid stimulating hormone in 103 rural subjects with respect to blood levels of organochlorine pesticide and occupation. We found that 24.3% of study subjects had depleted thyroxine levels in association with significantly lower organochlorine pesticide residues in blood. Sex, nutritional status, thyromegaly, or handling of pesticides in the course of work were not found to be factors contributing to depleted thyroxine levels.

The role of human hairs in health and disease with special reference to environmental exposures.

Increasing use of chemicals and the resultant human exposure have put pressure on environmentalists to find new ways of monitoring human chemical uptake. Examination of hair is emerging as a useful tool for the assessment of exposure loads for certain toxicants and pollutants and can be effectively used for monitoring and preventing environmental and occupational morbidity in specific population groups. Hair is an easily available biological tissue which, because of its typical morphology, reflects disease conditions within the body. It also provides a permanent record of the trace elements associated with normal and abnormal metabolism, as well as those elements assimilated from the environment.

Dermal toxicity of nickel and chromium in guinea pigs.

Liver and kidney enzyme activities and blood glucose and hemoglobin increased after 15 or 30 d of dermal exposure to nickel and chromium. Concentration of nickel and chromium increased in tissues. The changes were related to the duration of exposure.

A study of extra-auditory effects of noise.

Paper mill workers (106) exposed to noise ranging from 80 to 96 dBA were assessed for alteration in clinical status. Neurobehavioral functions were examined with the help of a questionnaire. The study did not reveal any changes attributable to noise in subjects exposed to 86-90 dBA and > 90 DBA noise in course of their occupations.

Multivariate analysis of byssinosis risk assessment.

Multiple logistic regression model was used considering byssinosis as an independent variable, and dustiness, smoking, exposure years and age as explanatory variables. Dustiness and length of exposure to the dust were found to be the most important contributory factors to byssinosis prevalence. The risk of byssinosis among workers in card room, blow room and waste plant sections and those who had exposure of more than 5 years was nearly three times than that among workers of other sections of the mill and/or with less than 5 years of exposure.

Renal toxicity of nickel, sodium lauryl sulphate and their combination after dermal application in guinea pigs.

The guinea pigs were dermally exposed to nickel (Ni), sodium lauryl sulphate (SLS) and in their combination for 7 and 14 days. The exposure to Ni and SLS produced changes in enzymes and lipid peroxidation in kidney. The exposure to Ni or SLS depicted slight changes while combined exposure to Ni plus SLS exhibited more degenerative changes in kidney. The result of the study suggests that industrial workers and/or populations exposed simultaneously to Ni and SLS produces more damage to kidney.

Socioeconomic and health status of electronics workers employed in organized industry.

To study their socioeconomic and health status, 1,770 workers in the organized electronics industry in India were surveyed. Mean age of the workers employed in this industry was 32.5 +/- 6.01 years. The average per capita income/month was Rupees 333, indicating a higher socioeconomic status, compared with the status of the national population, as well as compared with their counterparts in the unorganized sectors. Respiratory symptoms and impairment rates were significantly higher in workers exposed to soldering fumes. The high prevalence of congested or inflamed throat was also related to chemical exposure specially among solderers and workers exposed to metal oxides. The ocular symptoms and signs were also related to chemical exposure. Musculoskeletal disorders were related to erratic ergonomic postures.

Clinical studies of employees in a sheet-forming process at a paper mill.

Formaldehyde resins are used to improve the wet strength of paper. During the sheet-forming process of paper manufacture, formaldehyde fumes are liberated. Twenty-two male subjects having such exposures in a paper mill and 27 unexposed subjects were clinically evaluated to determine the effect of low level formaldehyde exposure in a tropical country. The workers were exposed to 0.03 mg formaldehyde/m3 air as an 8-h TWA. Formic acid excretion in urine was 37.2 +/- 18.9 and 20.3 +/- 4.2 ug/L among the exposed and the unexposed subjects, respectively. Significantly more respiratory problems (31.8%) were observed among the exposed subjects as compared to controls. Complaints pertaining to gastrointestinal, musculoskeletal and cardiovascular systems were also more frequent in exposed subjects. In spite of formaldehyde concentrations being well within the prescribed ACGIH limits of 1 ppm, the high rates of sickness emphasise the need for detailed studies on formaldehyde-exposed subjects in tropical countries.

Dermal toxicity of paraphenylenediamine.

The guinea pigs were dermally exposed to paraphenylenediamine (PPD) and in presence of an oxidising agent hydrogen peroxide for 15 and 30 d to assess their effects on some enzymes, lipid peroxidation and histamine contents in the skin. The activities of acid and alkaline phosphatases, beta-glucuronidase, gamma glutamyl transpeptidase, histidase and tyrosinase were enhanced after application of either PPD or PPD plus hydrogen peroxide. The lipid peroxidation and histamine contents also showed marked elevation following exposure to the chemicals.