Industrial hygiene survey in an aluminium reduction plant in India.

This study reports a work-environmental assessment and workers' exposure in a major prebake type aluminium smelter in India. Levels of known health hazards in and near the main smelting operations viz., the Potroom, the Carbon area, the Butt section, the Rodding shop, the Bath preparing area and the Casthouse were measured. Dustiness in general was high to excessively high. Mean levels of respirable dust (PM10) in air in the three dustiest areas were 24.07 mg/m3 in the Carbon areas, 27.57 mg/m3 in the Bath preparing and 4.44 mg/m3 in the Rodding shop. 40- 60% of the particles were less than 5 microm in size. 0.5- 2.82% particulate fluoride was obtained in the size fraction 0.4- 4.7 microm of the Potroom air. Naturally, exposures to total dusts were very high in these processes. The background levels of NOx and SO2 and fluorides (gaseous and particulate) were found to be within the prescribed Indian Standards. Higher exposures to gaseous and particulate fluoride, 3.85 and 6.53 mg/m3 respectively, were observed among the Rodding shop workers. The levels ofpolycyclic aromatic hydrocarbons (PAHs) were deemed to be excessive in the Carbon area. Measurements of heat stress were made in winter and were found to be lower than the prescribed limit.

Multi-organ toxicity and death following acute unintentional inhalation of paint thinner fumes.

BACKGROUND: Paint thinners containing a mixture of volatile organic solvents have considerable potential for solvent abuse. Deaths from solvent inhalation have been reported but most of them relate to intentional solvent abuse and occur soon after exposure. Accidental death due to unintentional inhalation of solvent vapors can also occur suddenly but more often, death results from late complications secondary to multi-organ toxicity. Malfunctioning of the cardiorespiratory, renal, and central nervous systems as a result of latent-toxic effects of solvent exposure has received little attention. CASE REPORT: An adult male unintentionally inhaled an excessive amount of paint thinner vapors and immediately developed central nervous system effects, followed by severe cardiorespiratory and renal pathologies that ultimately led to death 11 days after exposure. CONCLUSION: Acute unintentional inhalation of paint thinner fumes resulted in serious multi-organ toxicity and death. This case strongly suggests the need to employ suitable precautionary measures while handling volatile organic solvents in a confined area.

Tuberculosis among workers exposed to free silica dust.

Tuberculosis (TB) is a global emergency. Poverty, increasing migration, homelessness and the compulsions to live and work in high-risk environments are making people increasingly susceptible to the disease. Those working in mines, construction work, stone-crushing and in other similar occupations where there is a greater level of exposure to silica dust are specially vulnerable. Though the association between TB and silicosis has been firmly established by the results of epidemiologic studies no attempts have been made to study the epidemiological features of radiologically active TB among free silica exposed workers. Thus the cross sectional study was carried out among slate pencil workers and quartz stone crushers to assess the prevalence of TB and some associated epidemiological factors. It included 253 quartz workers and 102 slate pencil workers. Clinical history and chest radiographs were used for labeling the subjects as tuberculotic. The pulmonary functions of the subjects were measured using Spirovit SP- 10. Statistical analysis was carried out using statistical software package Epi Info 3.3.2. Among stone crushers the prevalence of TB was found to be 10.7% while among slate pencil workers it was as high as 22.5%. Among the quartz stone-crushers the workers aged ≥35 years, those exposed for ≥3 years and those who were smokers had higher risk TB while among the slate pencil workers, only those exposed for ≥10 years had higher risk. Though the FVC and FEV(1) values of the workers having TB were lower than those having normal radiographs, the differences were found to statistically non-significant.

Semen quality of industrial workers occupationally exposed to chromium.

A total of sixty-one subjects occupationally exposed to chromium in an industry which manufactures chromium sulphate and fifteen control subjects from a nearby industry which does not manufacture any chromium related compounds were studied. The history of each subject was recorded on pre-designed form through interview and a routine medical examination was carried out. Blood samples (5-6 ml) were collected for the estimation of chromium and semen samples were collected for semen analysis and the determination of copper and zinc levels in the seminal plasma. Clinical examination revealed nasal perforation in 10 subjects (out of 61) in the exposed group as compared to none in the control group. A significantly higher level of chromium was observed in the blood of the exposed workers as compared to the control. The concentration of zinc in seminal plasma was lower while the level of copper was higher in the exposed group as compared to the control. However, these changes were not statistically significant. Statistically significant higher numbers of morphologically abnormal sperms were noticed in the exposed group with respect to the control. Further analysis of the data indicated that about 53% of the exposed subjects showed less than 30% normal forms as compared to 10% in control subjects. However, no significant alterations in semen volume, liquefaction time, mean pH value, sperm viability, concentration or motility, were noticed between chromium exposed and unexposed workers. The data also indicates that exposure to chromium has some effect on human sperm as a significant positive correlation (r=0.301) was observed between percentages of abnormal sperm morphology and blood chromium levels (p=0.016) after pooling all the data of the control and exposure groups.

Assessment of respirable dust and its free silica contents in different Indian coalmines.

Assessment of respirable dust, personal exposures of miners and free silica contents in dust were undertaken to find out the associated risk of coal workers' pneumoconiosis in 9 coal mines of Eastern India during 1988-91. Mine Research Establishment (MRE), 113A Gravimetric Dust Sampler (GDS) and personal samplers (AFC 123), Cassella, London, approved by Director General of Mines Safety (DGMS) were used respectively for monitoring of mine air dust and personal exposures of miners. Fourier Transform Infra-red (FTIR) Spectroscopy determined free silica in respirable dusts. Thermal Conditions like Wet Bulb Globe Temperature (WBGT) index, humidity and wind velocity were also recorded during monitoring. The dust levels in the face return air of both, Board & Pillar (B&P) and Long Wall (LW) mining were found above the permissible level recommended by DGMS, Govt. of India. The drilling, blasting and loading are the major dusty operations in B&P method. Exposures of driller and loader were varied between, 0.81-9.48 mg/m3 and 0.05-9.84 mg/m3 respectively in B&P mining, whereas exposures of DOSCO loader, Shearer operator and Power Support Face Worker were varied between 2.65-9.11 mg/m3, 0.22-10.00 mg/m3 and 0.12-9.32 mg/m3 respectively in LW mining. In open cast mining, compressor and driller operators are the major exposed groups. The percentage silica in respirable dusts found below 5% in all most all the workers except among query loaders and drillers of open cast mines.

Peak expiratory flow and respiratory morbidity: a study among silica-exposed workers in India.

BACKGROUND: The present cross-sectional study was carried out among 136 quartz stone grinders with the objective of studying the peak expiratory flow (PEF) and the associated epidemiological factors. METHODS: Interview technique was used to record demographic characteristics and occupational history on a predesigned proforma, which included questionnaires regarding demographic, occupational and clinical characteristics. This was followed by complete medical examination and measurement of PEF using Spirovit SP-10. The study included 75 (55.1%) male and 61 (44.9%) female silica-exposed workers. The mean age of the subjects was 31.77 +/- 9.99 years whereas the mean duration of exposure was 2.74 +/- 1.65 years. The mean PEF was found to be 5.16 +/- 2.1 L/min. RESULTS: In the present study the PEF was significantly reduced in those having respiratory morbidity on both unadjusted and adjusted analyses. CONCLUSIONS: This suggests that along with the restrictive pathology caused by free silica dust, obstructive changes are also encountered in silica-exposed workers.

Repeated episodes of endosulfan poisoning.

INTRODUCTION: A number of families in a rural area of Jabalpur District (Madhya Pradesh), India, were affected by repeated episodes of convulsive illness over a period of three weeks. The aim of this investigation was to determine the cause of the illness. METHODS: The investigation included a house-to-house survey, interviews of affected families, discussions with treating physicians, and examination of hospital records. Endosulfan poisoning was suspected as many villagers were using empty pesticide containers for food storage. To confirm this, our team collected blood and food samples, which were transported to the laboratory and analyzed with GC-ECD. RESULTS: Thirty-six persons of all age groups had illness of varying severity over a period of three weeks. In the first week, due to superstitions and lack of treatment, three children died. In the second week, symptomatic treatment of affected persons in a district hospital led to recovery but recurrence of convulsive episodes occurred after the return home. In the third week, 10 people were again hospitalized in a teaching hospital. Investigations carried out in this hospital ruled out infective etiology but no facilities were available for chemical analysis. All persons responded to symptomatic treatment. The blood and food samples analyzed by our team showed presence of endosulfan, which was confirmed by GCMS. One of the food items (Laddu) prepared from wheat flour was found to contain 676 ppm of alpha-endosulfan. CONCLUSIONS: Contamination of wheat grains or flour with endosulfan and its consumption over a period of time was the most likely cause of repeated episodes of convulsions, but the exact reason for this contamination could not be determined. This report highlights the unsafe disposal of pesticide containers by illiterate farm workers, superstitions leading to delay in treatment, and susceptibility of children to endosulfan.

Occupational health research in India.

India being a developing nation is faced with traditional public health problems like communicable diseases, malnutrition, poor environmental sanitation and inadequate medical care. However, globalization and rapid industrial growth in the last few years has resulted in emergence of occupational health related issues. Agriculture (cultivators i.e. land owners + agriculture labourers) is the main occupation in India giving employment to about 58% of the people. The major occupational diseases/morbidity of concern in India are silicosis, musculo-skeletal injuries, coal workers' pneumoconiosis, chronic obstructive lung diseases, asbestosis, byssinosis, pesticide poisoning and noise induced hearing loss. There are many agencies like National Institute of Occupational Health, Industrial Toxicology Research Centre, Central Labour Institute, etc. are working on researchable issues like Asbestos and asbestos related diseases, Pesticide poisoning, Silica related diseases other than silicosis and Musculoskeletal disorders. Still much more is to be done for improving the occupational health research. The measures such as creation of advanced research facilities, human resources development, creation of environmental and occupational health cells and development of database and information system should be taken.

Airborne endotoxin and its relationship to pulmonary function among workers in an Indian jute mill.

Air samples from various processing areas of an Indian jute mill were examined for endotoxin. The authors assessed work-related respiratory symptoms and pulmonary function changes in the dust-exposed workers from the different processing areas using a standard questionnaire and spirometry. Endotoxin was estimated in water extract of jute dust from 3 milling areas, and in outside air, by the Limulus amebocyte lysate gel clot technique. The batching, spinning, and weaving areas of the jute mill showed endotoxin levels of 0.22-4.42 microg/m3, 0.04-1.47 microg/m3, and 0.01-0.07 microg/m3, respectively, values similar to those found in Indian cotton mills. Respiratory morbidities among the workers included typical byssinotic symptoms, along with acute changes in postshift forced expiratory volume in 1 s (FEV1.0) (31.8%). Results of this study demonstrated that increased exposure to bacterial endotoxin in airborne dust is related to byssinotic symptoms among Indian jute mill workers. Findings were similar to those reported previously for workers in the cotton, flax, and hemp industries.

Serum copper levels among quartz stone crushing workers: a cross sectional study.

The present cross sectional study was carried out among 134 workers of quartz stone crushing units to assess the serum Cu activity among quartz stone workers without disease. Demographic and occupational details of the subjects were recorded on the predesigned proforma. Standard diagnostic criteria were used for diagnosing silicosis and tuberculosis. The pulmonary functions of the subjects were measured using Spirovit SP-10. The mean age for male was found to be 26.63 +/- 6.28 years while that for female was 21.93 +/- 4.29 years and for the whole group was 26.13 +/- 6.26 years. In the present study only one case of silicosis and seven cases of tuberculosis were found. The mean serum Cu levels of those having respiratory disease was found to be 91.5 +/- 19.8 microg/dl while mean serum Cu level of those free from respiratory disease was 86.8 +/- 21.3 microg/dl The difference was found to be statistically non-significant (t = 0.64, df= 1, P > 0.05). Thus, in the present study, though the elevated level of serum Cu was found in solitary case of silicosis, no association could be established between the silica exposure and serum copper levels as suggested by non-significant effect of duration of exposure (P = 0.53).

Spirometric measurements among quartz stone ex-workers of Gujarat, India.

The present cross sectional study was carried out among 134 ex-workers from quartz stone crushing units. Using the interview technique as a tool for data collection, demographic and occupational details of the subjects were recorded on the predesigned proforma. Standard diagnostic criteria were used for diagnosing silicosis and silico-tuberculosis. The pulmonary functions of the subjects were measured with Spirovit SP-10. The mean age of the males was found to be 33.18 +/- 10.39 yr and that of the females was 30.10 +/- 9.3 yr and for the whole group was 31.77 +/- 9.99 yr. Mean duration of exposure was 2.74 +/- 1.65 yr. The study variables included age, sex, duration of exposure, smoking and respiratory morbidity. Forced Vital Capacity (FVC) which suggests lung parenchymal disorders was found to be significantly reduced with female sex, presence of smoking, increasing duration of exposure and presence of pneumoconiosis, whereas the lung function parameters indicating the status of airways were found to be significantly reduced with all the factors. Therefore, it was concluded that quartz stone workers exposed to approximately 100% free silica had deteriorated lung function which can be attributed mainly to respiratory disorders along with other epidemiological factors such as age, sex, duration of exposure and smoking.

Byssinosis among jute mill workers.

Although byssinosis in jute mill workers remains controversial, studies in a few jute mills in West-Bengal, India, revealed typical byssinotic syndrome associated with acute changes in FEV1 on the first working day after rest. The present study on 148 jute mill workers is reported to confirm the occurrence of byssinosis in jute mill workers. Work related respiratory symptoms; acute and chronic pulmonary function changes among exposed workers were studied on the basis of standard questionnaire and spirometric method along with dust level, particle mass size distributions and gram-negative bacterial endotoxins. The pulmonary function test (PFT) changes were defined as per the recommendation of World Health Organization and of Bouhys et al. Total dust in jute mill air were monitored by high volume sampling, technique (Staplex, USA), Andersen cascade impactor was used for particle size distribution and personal exposure level was determined by personal sampler (Casella, London). Endotoxin in airborne jute dust was analysed by Lymulus Amebocyte Lysate (LAL) "Gel Clot" technique. Batching is the dustiest process in the mill. Size distribution showed that about 70-80% dust in diameter of < 10 microm, 40-50%, < 5 microm and 10-20%, < 2 microm. Mean endotoxin levels found in hatching, spinning and weaving, and beaming were 2.319 microg/m3, 0.956 microg/ m3, 0.041 microg/m3 respectively and are comparable to the values obtained up to date in Indian cotton mills. Respiratory morbidity study reported typical byssinotic symptoms along with acute post shift FEV1 changes (31.8%) and chronic changes in FEV1 (43.2%) among exposed workers. The group with higher exposure showed significantly lower FVC, FEV1, PEFR and FEF25-75% values. The study confirmed the findings of the earlier studies and clearly indicated that the Indian jute mill workers are also suffering from byssinosis as observed in cotton, flask and hemp workers.

Integrated pest management and residue levels of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) in water samples from rural areas in Gujarat State, India.

The authors identified 2 rural areas for study in Gujarat State, India, on the basis of pesticide use in agriculture and vector-control programs. In rural area 1, pesticides were used in both agriculture and vector-control programs, whereas in rural area 2, they were used in agriculture only. Water samples were collected from both areas, and they were analyzed for total dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) residues. The mean residue levels of total DDT in rural areas 1 and 2 were 7.56 ng/l and 4.27 ng/l, respectively. The corresponding values for HCH were 6.96 ng/l and 5.53 ng/l, respectively. Residue levels of both pesticides were significantly lower in rural area 2 than in area 1.