Subodh K. Rastogi

A study on oxidative stress and antioxidant status of agricultural workers exposed to organophosphorus insecticides during spraying.

Oxidative stress status and Acetylcholinesterase (AChE) activity were studied in blood samples obtained from 61 agricultural workers engaged in spraying organophosphorus (OP) insecticides in the mango plantation, with a minimum work history of one year, in the age range of 12-55 years. Controls were age-matched, unexposed workers, who never had any exposure to OP pesticides. They were evaluated for oxidative stress markers MDA (end product of lipid peroxidation), reduced glutathione (GSH), and Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) levels in blood. The results showed a marked inhibition of the AChE and BChE activities in the sprayers as compared to the controls. The malondialdehyde(MDA), the last product of lipid peroxidation was found to be increased significantly in sprayers(p<0.05), while depletion in the concentration of antioxidant glutathione(GSH) was also observed in the sprayers but the difference was statistically not significant. It was concluded on the basis of biochemical analysis that pesticides sprayers are exposed to more oxidative stress as evidenced by the changes in antioxidant status. The measurement of the AChE and BChE activities in agricultural workers who spray OPs could be a good biomonitoring factor and is recommended to be performed on a regular basis.

Renal effects of environmental and occupational lead exposure.

Lead is one of the most useful elements in industry, but serves no useful function in the human body. Environmental and industrial lead exposures continue to pose major public health problems in the exposed population.[1] Over the years, it has become increasingly evident that low-level lead exposure resulting in blood lead levels between 10 and 15 μg/dL can lead to deleterious effects like cognitive impairment and behavioral deficits, high blood pressure (BP) and impaired renal function.[2,3] Lancereaux[4] provided the first description of kidney disease and interstitial nephritis by postmortem examination of a lead-poisoned artist. It was not until the late 1920s when an epidemic of chronic nephritis in Queensland, Australia, was linked to childhood lead poisoning that the full spectrum of lead-induced nephropathy became apparent.[5,6] This was followed by cases of renal diseases from the US in individuals consuming lead-contaminated illegally distilled moonshine whisky.[7]

Occupational health risks among the workers employed in leather tanneries at Kanpur.

In a cross-sectional study, a random sample of 197 male workers drawn from different sections of 10 leather tanneries in Kanpur were selected for the assessment of health risks. A control group comprising of 117 male subjects belonging to a similar age group and socioeconomic strata, who never had any occupational exposure in the leather tanneries, were also examined for the comparison purpose. The findings revealed a significantly higher prevalence of morbidity among the exposed workers in contrast to that observed in the controls (40.1% vs. 19.6%). The respiratory diseases (16.7%) were mainly responsible for a higher morbidity among the exposed workers whereas the gastrointestinal tract problems were predominant in the control group. The urinary and blood samples collected from the exposed group showed significantly higher levels of chromium, thereby reflecting the body burden of Cr in the exposed workers as a result of a high concentration of environmental Cr at the work place.

Respiratory Health Effect from Occupational Exposure to Wood Dust in Sawmills

Spirometric lung functions were recorded for 109 workers (mean age 26.4 +/- 8.2 yr) occupationally exposed (mean exposure 8.9 +/- 7.7 yr) to soft wood dust in local sawmills along with 88 unexposed controls (mean age 28.7 +/- 9.9 yr) belonging to the same socioeconomic status to assess the prevalence of respiratory impairment in the exposed population. The results of the study showed a significantly higher prevalence of overall respiratory impairment in the exposed group even after standardizing for smoking habits (p less than 0.001). The adjusted rate for respiratory impairment in the exposed group was 29.4% as compared to 2.2% observed in the unexposed controls. The pattern of respiratory abnormality observed in the sawmill workers was predominantly the restrictive type (28.4%), indicating lower levels of forced vital capacity (FVC) in the exposed group; while in the control group, there were none with lung restriction The prevalence of airflow limitation, however, was similar in the exposed workers (1.8%) and controls (2.2%), thereby, indicating that bronchial obstruction was independent of wood dust exposure. It is concluded that the dust exposure in sawmills is associated mainly with restrictive type of pulmonary impairment in the exposed workers.

Multipronged evaluation of genotoxicity in Indian petrol‐pump workers

Petrol (gasoline) contains a number of toxicants. This study used human biomonitoring to evaluate the genotoxic effects of exposure to benzene in petrol fumes in 100 Indian petrol‐pump workers (PPWs) and an equal number of controls. The study was corroborated with in silico assessments of the Comet assay results from the human biomonitoring study. An in vitro study in human lymphocytes was also conducted to understand the genotoxicity of benzene and its metabolites. In a subset of the population studied, higher blood benzene levels were detected in the PPWs (n = 39; P < 0.01) than the controls (n = 18), and 100–250 ppb benzene was also detected in air samples from the petrol pumps. PPWs had higher levels of DNA damage than the controls (P < 0.01). In addition, the micronucleus assay was performed on lymphocytes from a subset of the subjects, and the micronucleus frequency for PPWs was significantly higher (n = 39; 14.79 ± 3.92‰) than the controls (n = 18; 7.54 ± 3.00‰). Human lymphocytes were treated in vitro with benzene and several of its metabolites and assayed for DNA damage with the Comet assay. Benzene and its metabolites produced significant (P < 0.05) levels of DNA damage at and above concentrations of 10 μM. The metabolite, p‐benzoquinone, produced the greatest amount of DNA damage, followed by hydroquinone > benzene > catechol > 1,2,4,‐benzenetriol > muconic acid. This study demonstrates that, using sensitive techniques, it is possible to detect human health risks at an early stage when intervention is possible. possible. Environ. Mol. Mutagen., 2008.

Spirometric abnormalities among welders

A group of manual welders (N = 57) engaged in gas welding joint faces of moulded brasswares, age group 13-60 years (mean: 29.2 +/- 1.37 years), having a mean exposure period of 12.4 +/- 1.12 years (range: 1-35 years) were subjected to spirometry to evaluate the prevalence of spirometric abnormalities. The findings were compared with those obtained from a reference group (N = 131) (mean age: 31.2 +/- 1.35 years) engaged in nonwelding jobs such as packing, labelling, and transportation of the finished brassware articles. The welders showed a significantly higher prevalence of respiratory impairment (28.0%) than that observed among the unexposed controls (6.1%) (P less than 0.001), as a result of exposure to welding gases which comprised fine particles of lead, zinc, chromium, and manganese. This occurred despite the lower concentration of the pollutants at the work place. In the exposed group, the smoking welders showed a prevalence of respiratory impairment significantly higher than that observed in the nonsmoking welders (40.0 vs 18.7%) (P less than 0.10). A similar trend was observed in the control group indicating that smoking had a deteriorating effect on spirometric tests. The results of the pulmonary function tests showed a predominantly restrictive type of pulmonary impairment (12.3%) followed by a mixed ventilatory defect (8.7%) among the welders. The effect of age on pulmonary impairment was not discernible either in the exposed or unexposed group. The analysis of data in relation to duration of exposure showed significant correlation between the prevalence of respiratory abnormalities and length of exposure. Welders exposed for over 10 years showed a prevalence of respiratory abnormalities significantly higher than those exposed for less than 10 years (44.4 vs 13.3%) (P less than 0.01) thereby showing that occupational exposure to welding fumes resulted in increased prevalence of pulmonary impairment in the welders. Smoking also had a contributory role thereby suggesting an interaction between smoking and welding exposure on the prevalence of pulmonary impairment in the welders engaged in brassware industries.

A study of neurologic symptoms on exposure to organophosphate pesticides in the children of agricultural workers

Pesticides are used extensively throughout the world in agriculture and in pest control as well as for community health purposes. Organophosphate (OP) pesticide self-poisoning is an important clinical problem in rural regions of the developing world that kills an estimated 200,000 people every year. Unintentional poisoning kills far fewer people but is an apparent problem in places where highly toxic OP pesticides are available. Neurologic dysfunction is the best documented health effect of pesticide exposure. High-level exposure has both acute and long-term neurologic signs and symptoms, and adverse effects have been reported in most type of pesticides, including organophosphate (OP), carbamate, organochlorine, and pyrethroid insecticides, herbicides, fungicides, and fumigants. Acute OP pesticide exposure can involve in wide range of both central and peripheral neurologic symptoms. Increased neurologic symptom prevalence may provide early evidence of neurologic dysfunctions, before clinically measurable signs are evident. In this study, we analyzed the cross-sectional data on neurologic signs and symptoms from 225 rural children, both males (n = 132) and females (n = 93) who were occupationally and paraoccupationally exposed to methyl OPs (dichlorvos, fenthion, malathion, methyl parathion) and ethyl OPs (chlorpyrifos, diazinon, ethyl parathion) as they belonged to agricultural families handling, mixing, and spraying the OP pesticides. The children completed a specially designed questionnaire (Q16) on neurologic symptoms associated with pesticide exposure with their parental help. A suitable reference group consisting of rural children (n = 50) never involved in pesticide handling (neither outdoor nor indoor) belonging to similar socioeconomic strata included in the study to compare the prevalence of various neurologic symptoms between the two groups. Among all the neurologic self-reported symptoms, headache, watering in eyes, and burning sensation in eye/face were the most important clinical manifestations attributed to OP pesticide exposure. These symptoms could probably be the consequence of chronic effects of most pesticides on the central nervous system. The muscarinic symptoms reported the maximum prevalence of salivation (18.22%), whereas lacrimation was observed in 17.33% cases, followed by diarrhea in 9.33% cases. The nicotinic clinical manifestations of acute OP poisoning revealed excessive sweating in 13.78% cases and tremors in 9.3% cases followed by mydriasis in 8.4% exposed children. The characteristic cholinergic symptoms, such as insomnia, headache, muscle cramps, weakness, and anorexia were also reported by both male and female exposed children. The high frequency of neurologic symptoms observed in the study may be due to parasympathetic hyperactivity due to the accumulated ACh resulting from AChE inhibition.

Possible mechanism of pesticide toxicity-related oxidative stress leading to airway narrowing

Abstract The study was conducted to assess the magnitude of oxidative stress and lung function abnormalities in 34 male pesticide sprayers on exposure to pesticides in mango plantations. Biochemical studies on blood antioxidant enzymes revealed an unchanged glutathione level and increased level of malondialdehyde (P < 0.001), which indicates that pesticide sprayers may have suffered from oxidative stress. Decreased acetyl-cholinesterase levels (P < 0.001) in sprayers compared to the controls suggest inhibition of cholinesterase activity. The present study shows that pesticide toxicity might lead to oxidative stress and airway narrowing resulting in decreased peak expiratory flow rate.

A study of the prevalence of respiratory morbidity among agate workers.

SummaryA random sample of 342 workers engaged in chipping and grinding of agate stones were surveyed in a cross-sectional study to assess the prevalence of respiratory morbidity in the agate industry. The findings were compared with those obtained in controls. The study showed a significantly higher prevalence of lung diseases among agate workers than among controls (63.4% vs 35.5%, P < 0.001). The respiratory morbidity in agate workers and controls was maximal in the group aged 31+ years (83.3% and 42.2%, respectively). The prevalence of pneumoconiosis in agate workers (18.4%) was highly significant as compared with controls, in whom not a single case was found (P < 0.001). However, there was no significant difference between the prevalence of pneumoconiosis in men and women of the exposed group (17.9% vs 19.6%). Among the cases of pulmonary diseases in agate workers, pneumoconiosis formed the largest group (18.4%), whereas among controls it was tuberculosis (12.1%). The prevalence of pulmonary tuberculosis was very high in both agate workers and controls (15.5% and 12.1%, respectively), probably because of poor socio-economic and unhygienic living conditions. The prevalence of chronic bronchitis was found to be higher among the control population as compared with the exposed group (6.7% vs 2.6%). It therefore appeared that agate dust had no role in precipitating chronic bronchitis. However, bronchial asthma appeared to have been aggravated due to agate dust, as the risk among agate workers was 7-fold that found among the controls. The prevalence of pneumoconiosis showed a dose-response relationship in both male and female agate workers. Pulmonary tuberculosis and bronchial asthma did not show any significant trend in relation to the duration of exposure. Other lung diseases were also independent of exposure. As far as occupations are concerned, grinders were found to suffer more from pneumoconiosis (21.9%) than did chippers (7.3%, P < 0.05); this was because the respirable dust concentration at the workplace of grinders was 6-fold that at the workplace of chippers. Acute bronchitis was also more prevalent in grinders (P < 0.05). However, tuberculosis and asthma did not vary significantly between the two occupational groups.

Monitoring of plasma butyrylcholinesterase activity and hematological parameters in pesticide sprayers.

To evaluate the health impact of spraying organophosphorus insecticides (OPs), 34 male sprayers in the mango belt of Malihabad, a small town located 27 km from Lucknow in North India was selected. Plasma butyryl cholinesterase (PBChE) and complete blood count were assessed among sprayers after spraying pesticides and the findings obtained were compared with those determined in a reference group (n = 18). The most common symptoms observed were burning sensation in the eyes (8.82%), itching/skin irritation (23.52%) and chest symptoms (32.35%) in the exposed workers. Plasma butyrylcholinesterase (PBChE) was significantly decreased in workers. The results indicated significant decrease in the mean value of hemoglobin, hematocrit and platelets count; however, significantly higher count of leukocytes was also observed in the exposed group (sprayers) compared to that observed in the control group (P < 0.05). Monitoring of PBChE in pesticide sprayers could be useful to predict and prevent health hazards of OPs.