[A study on the relationship between in-door air pollution and chronic obstructive pulmonary disease in Xuanwei County]

A cross-sectional study was conducted to explore the relationship between in-door air pollution caused by different fuels for domestic use and chronic obstructive pulmonary disease (COPD) in local population. A total population of 10892 were sampled and analyzed. Results showed in-door air pollution caused by coal-burning was the major risk factor for COPD in Xuanwei County. The risk of residents using soft coal and anthracite to suffer from COPD was 4.36 and 1.55 times, respectively, higher than in those using fire wood.

Cancer risk in asphalt workers and roofers: review and meta-analysis of epidemiologic studies

Twenty epidemiologic studies have described cancer risk in asphalt workers and roofers in various countries. A current concern for these workers is the potential carcinogenicity posed by inhalation of bitumen fumes or dermal exposure to bitumens. Bitumens are chemically different from many carcinogenic coal-tar based materials. Both have been employed in road paving and waterproofing. We examined and combined the results of the epidemiologic studies conducted on asphalt workers and roofers. We examined the cancer risk separately in three broad job categories: 1) roofers (exposed to bitumen fumes and previously often to coal-tar fumes); 2) highway maintenance workers (HMWs) and road pavers (exposed to bitumen fumes as well as possibly coal-tar fumes previously); and 3) miscellaneous and unspecified bitumen/asphalt workers. In roofers, an increased risk was suggested for cancers of the lung (aggregated relative risk 1.8, 95% confidence interval 1.5-2.1), stomach (1.7, 1.1-2.5), nonmelanoma skin (4.0, 0.8-12), and leukemia (1.7, 0.9-2.9). Some of the excesses may be attributable to polycyclic aromatic hydrocarbons (PAH) from coal-tar products. The aggregated relative risks in road pavers and HMWs were consistently lower than in roofers for cancers of the lung (0.9, 0.8-1.0), stomach (1.1, 0.8-1.5), bladder (1.2, 0.7-1.8), skin (2.2, 1.2-3.7), and leukemias (1.3, 0.9-1.8). Their risk of skin cancer was significantly increased, based on one study. Miscellaneous and unspecified workers had a significant excess (1.5, 1.2-1.8) of lung cancer. The data were poorly focused to address the carcinogenicity of bitumen fumes, as contrasted with tar-derived exposures. For the prospect of shedding more light on the bitumen-cancer controversy, the feasibility of a powerful multicenter cohort is currently being studied by the International Agency for Research on Cancer (IARC).

Dust exposure indices and lung function changes in longshoremen and dock workers

A group of Dutch harbor workers involved in loading and unloading bulk products from sea vessels such as coal, cokes, and some other products like alumina, borax, phosphate ore, and vermiculite was studied. Exposures were characterized by personal and environmental monitoring. This information was subsequently used to estimate several dust exposure indices and to study relationships with lung function variables and respiratory symptoms. Average respirable dust exposure levels ranged from 0.3-4.0 mg/m3. Workers involved in unloading products from sea vessels were exposed to the highest dust levels. Supervisors and workers with tasks in the dock had an intermediate to low exposure. Office workers had the lowest exposure to respirable dust. Inhalable dust levels were considerably higher and average exposures ranged from 0.3-80 mg/m3. The ranking of occupational titles by inhalable dust exposure was almost identical to the rank order of respirable dust levels. Workers with higher current and cumulative dust exposures tended to have a lower lung function, and only shortness of breath had a statistically significant relationship with current and cumulative inhalable dust exposure. In general, relationships between lung function and inhalable dust levels tended to be somewhat stronger in terms of statistical significance, because inhalable dust is an estimate of dust deposition in the upper airways and lung function is a measurable parameter of airway obstruction in that region. However, the differences with respirable dust were minimal, and variability in dust exposure levels was extremely large for this population. It was concluded that harbor workers involved in unloading ships containing coal and various kinds of ore can be exposed to high dust levels. Relationships between dust exposure and lung function illustrate that these exposures are a respiratory hazard. Our finding that inhalable dust levels have a somewhat stronger relationship with lung function level than respirable dust levels deserves further attention.

Biological markers and occupational lung disease: mineral dust-induced respiratory disorders

There is a need for methods to monitor early adverse effects, exposure, and/or susceptibility of individual subjects due to occupational and environmental causes. This paper discusses the experimental origin, value, and validity of several biological indicators, termed biomarkers, that were used to study coal dust-induced respiratory disorders. The findings are presented in a framework to visualize problems and challenges when developing biomarkers. Taking the framework of mineral dust-induced lung disorders as an example, it is demonstrated how carefully designed follow-up studies are a prerequisite to test the validity and use of events often put forward as biomarkers. It is concluded from the data that serum type III procollagen is neither an exposure nor an (early) effect marker, antioxidant enzyme expression is related to the early inflammatory response after mineral dust inhalation, while the evidence is accumulating that tumor necrosis factor-alpha is a susceptibility marker for progression in mineral dust-induced lung fibrosis.

Respiratory effects of coal dust exposure: clinical effects and diagnosis

During the past two decades, growing evidence has been reported on the role of respirable inorganic dust in the development of airflow obstruction, impaired diffusion capacity, chronic bronchitis, and emphysema, irrespective of the extent of possible pneumoconiotic abnormalities. These nonpneumoconiotic effects associated with dust exposure in miners and the relationship between dust exposure and mortality are reviewed. When pneumoconiotic changes can be visualized by different radiologic techniques, including computed tomography (CT) and high-resolution CT, assessment of the respiratory impairment in coal workers at present requires evaluation of the ventilatory and gas exchange capacity.

Past exposure to asbestos and combustion products and incidence of cancer among Finnish locomotive drivers

Locomotive drivers in the steam engine era were exposed to asbestos during their vocational training for two years while training in workshops. Later in their career they had exposure to coal and diesel combustion products. To assess the level of earlier exposure historical working conditions were reconstructed and hygienic conditions were measured. The average exposure to asbestos (mainly anthophylline) fibres > 5 microns was 5.0 fibres/cm3. Incidence of cancer in a cohort of 8391 members of the Finnish Locomotive Drivers' Association, 1953-91, was analysed. The incidence of lung cancer and also total cancer was below the national average, probably due to the low prevalence of smoking among the drivers in the steam engine era. A four-fold risk of mesothelioma was found, most likely caused by exposure to asbestos. Also the observed 1.5-fold incidence of non-melanoma skin cancer and 1.7-fold risk of cancer of the oral cavity and pharynx may be related to occupation.

Respiratory morbidity in Merseyside schoolchildren exposed to coal dust and air pollution

A cross sectional study was carried out to determine whether schoolchildren in a specific locality exposed to pollution from steam coal dust have an excess of respiratory symptoms compared with children in control areas. A total of 1872 primary schoolchildren (aged 5-11 years) from five primary schools in the Bootle dock area of Liverpool (exposed area), five primary schools in South Sefton (control area), and five primary schools in Wallasey (control area) were studied. A questionnaire was distributed through the schools and was completed by the parents of the children. The questionnaire inquired about respiratory symptoms (cough, wheezing, and shortness of breath), allergy, atopy, smoking, and socioeconomic factors. Height, weight, and peak expiratory flow were measured. Compliance was good (92%) and similar in the three study areas. The children in the three areas were of similar mean age (7.5 years), height (1.24 m), sex ratio, and had a similar prevalence of paternal (6.2%) and maternal (7%) asthma. The exposed zone contained more unemployed parents (41, 29, and 29% respectively), more rented housing (64, 45, 34%), and more smoking parents (71, 60, 59%) than the control areas. Respiratory symptoms were significantly more common in the exposed area, including wheeze (25.0, 20.6, and 17.5%), excess cough (40.0, 23.4, and 25.1%), and school absences for respiratory symptoms (47.5, 35.9, and 34.9%). These differences remained significant even if the groups were subdivided according to whether or not parents smoked or were employed. Multiple logistic regression analysis confirmed the exposed zone as a significant risk factor for absenteeism from school due to respiratory symptoms (odds ratio 1.55, 95% confidence interval 1.17 to 2.06) after adjusting for confounding factors. Standard dust deposit gauges on three schools confirmed a significantly higher dust burden in the exposed zone. An increased prevalence of respiratory symptoms in primary schoolchildren exposed to coal dust is confirmed. Although the association with known coal dust pollution is suggestive a cross sectional study cannot confirm a casual relation and further studies are needed.

Airways obstruction, coal mining, and disability

It has recently been suggested that the inhalation of coal in the absence of complicated coal workers' pneumoconiosis (CWP) or smoking can lead to disabling airways obstruction. The cause of such obstruction has been variously attributed to emphysema or bronchitis. The frequency of significant airways obstruction in a group of United States coal miners seeking compensation for occupationally induced pulmonary impairment was therefore determined. In a sample of 611 "Black Lung" claimants there was only one subject who was a non-smoker and who in the absence of other non-occupationally related diseases,--for example, asthma and bronchiectasis--had sufficient airways obstruction to render it difficult for him to carry out hard labour. An alternative explanation for his reduced ventilatory capacity other than coal dust or smoking may be available. If the inhalation of coal dust in the absence of smoking and complicated CWP ever induces sufficient ventilatory impairment to preclude a miner from working, it is indeed rare.

Evaluation of exposure reducing measures on parameters of genetic risk in a population occupationally exposed to coal fly ash

In a previous study we found increased SCE frequencies in peripheral blood lymphocytes (PBLs) of workers occupationally exposed in a coal fly ash processing industry, as compared to a non-exposed control population. Shortly after this study, measures were taken in this plant to reduce fly ash levels. The objective of the present study, conducted 2 years later in the same plants, was to evaluate the effect of these measures with respect to genotoxic risk. A group of 18 male workers of the coal fly ash processing industry agreed to participate in the study. The control population consisted of 18 male workers from a flour processing industry, who were matched for age and smoking behavior. In contrast to our previous study, no increased SCE frequencies were found in PBLs of workers potentially exposed to coal fly ash when compared to the control group (mean SCEs: 6.4 +/- 1.2 and 7.0 +/- 0.9, respectively). In addition, no differences were observed between the exposed and control groups for frequencies of gene mutations at the hypoxanthine guanine phosphoribosyltransferase (hprt) locus in PBLs, for micronucleus frequencies using the cytokinesis block method, or for urinary mutagen excretion measured with Salmonella typhimurium tester strains TA98 and TA97 with and without metabolic activation. In smokers, however, SCE frequencies in PBLs were significantly increased in comparison to non-smokers (7.1 +/- 1.1 vs. 6.1 +/- 0.5; P < 0.005), as was 24-h urinary mutagen excretion measured with strain TA98 with S9 mix (2373 +/- 1870 vs. 156 +/- 211; P < 0.001) and with TA98 with S9 mix and beta-glucuronidase/arylsulfatase (2361 +/- 1958 vs. 538 +/- 396; P < 0.005). In addition, hprt variant frequencies in PBLs were higher in smokers than in non-smokers (15.0 +/- 23.5 x 10(-6)6 vs. 2.6 +/- 2.8 x 10(-6); P < 0.05). No differences were observed for micronucleus induction between smokers and non-smokers. It is concluded that the protective measures taken in the coal fly ash processing plant appear to have been sufficient, since an effect of exposure to coal fly ash on parameters of genetic risk was not found any longer.

Passive cigarette smoke, coal heating, and respiratory symptoms of nonsmoking women in China

In this study we evaluated data from a sample of 973 never-smoking women, ages 20-40, who worked in three similar textile mills in Anhui Province, China. We compared prevalence rates of respiratory symptoms across homes with and without coal heating and homes with different numbers of smokers. Multiple logistic regression models that controlled for age, job title, and mill of employment were also estimated. Respiratory symptoms were associated with combined exposure to passive cigarette smoke and coal heating. Effects of passive cigarette smoke and coal heating on respiratory symptoms appeared to be nearly additive, suggesting a dose-response relationship between respiratory symptoms and home indoor air pollution from these two sources. The prevalence of chest illness, cough, phlegm, and shortness of breath (but not wheeze) was significantly elevated for women living in homes with both smokers and coal heating.

Risk factors for lung cancer in non-smokers in Xuanwei County of China

Tobacco smoking and some types of occupational exposures have consistently been considered as important etiologic factors of lung cancer in industrial countries. At the First World Conference of Lung Cancer (Wyndwer, 1983), it was stressed that more attention should be paid to finding out the causes of lung cancer in non-smokers. In Xuanwei County, Yunnan Province, annual lung cancer death rate was 27.7 per 100,000 in males, among China's highest, and 25.3 per 100,000 in females, the China's highest. The female's lung cancer death rate in Xuanwei County was even much higher than that of the same period in USA white women (ECACM, 1979; Mulvihill, 1976). Marked district variation in cancer mortality exists within Xuanwei County. The county can be divided into high-, medium- and low-mortality areas. Over 90% of the population are farmers. The local residents traditionally burned three major kinds of fuels: "smoky" coal, "smokeless" coal and "wood", for heating and cooking. The three lung cancer high mortality areas, including "Chengguan", "Rongcheng" and "Laibin" communes, mainly burned the "smoky" coal from Laibin smoky-coal mine. The fuel was burned in a shallow, unventilated fire pit in the floor of the dwelling. Fuel burning in shallow unventilated pits has resulted in high indoor air pollution levels. The concentrations of airborne particles (pm 10) inside houses during smoky coal and wood combustion were very high. Indoor concentration of suspended particulates and dichloromethane extractable organics were 24.4mg/m3 and 17.6mg/m3 in burning of "smoky" coal; 22.3mg/m3, 12.3mg/m3 for burning wood; and 1.8mg/m3, 0.5mg/m3 for burning of smokeless coals.(ABSTRACT TRUNCATED AT 250 WORDS)

How silicosis and coal workers' pneumoconiosis develop--a cellular assessment

In vitro and in vivo animal studies, as well as human investigations, strongly support the role of macrophage products in the development and progression of silicosis and coal workers' pneumoconiosis. Such products include enzymes and reactive oxygen species which may cause lung damage; cytokines which recruit and/or activate polymorphonuclear leukocytes and thus result in further oxidant damage to the lung; and fibrogenic factors which induce fibroblast proliferation and collagen synthesis. This mechanistic understanding of pulmonary disease should assist in developing strategies for prevention and treatment.

Antithyroid effects of coal-derived pollutants

Endemic goiter in iodide-sufficient areas of the United States and Colombia has been linked to watersheds rich in coal and shale, which several reports suggest are the source of water-borne goitrogens. In this report the potential antithyroid activities of aqueous coal and shale extracts and of compounds identified in aqueous effluents from coal conversion processes were assayed in thyroid peroxidase (TPO) and thyroid slice systems. Aqueous extracts of coal and black shale were potent inhibitors of TPO or 125I organification by thyroid slices. The most abundant water-soluble compounds derived from coal are dihydroxy-phenols, thiocyanate, disulfides, and hydroxypyridines. The dihydroxyphenols resorcinol, 2-methylresorcinol, and 5-methylresorcinol (orcinol) were 26.7, 22.5, and 7.2 times more potent, respectively, than the antithyroid drug 6-propylthiouracil (PTU). Other dihydroxyphenols and thiocyanate were less potent but comparable in activity to PTU. All dihydroxypyridines and 3-hydroxypyridine produced inhibitory effects comparable to PTU. None of the disulfides inhibited TPO. The antiperoxidase effects of combinations of two dihydroxyphenols or one dihydroxyphenol and SCN were additive, whereas the effects of a combination of four dihydroxyphenols at threshold inhibitory concentrations were synergistic, resulting in net effects equivalent to or greater than the sum of the individual effects. Thus, antithyroid effects may be greatly amplified by exposure to multiple coal-derived goitrogens and could be many times that produced by any one of the contributing pollutants. These results demonstrate that potent water-borne goitrogens are derived from coal and shale and that their contamination of water supplies could pose a serious threat of thyroid disorders.

Persistent inflammation and impaired chemotaxis of alveolar macrophages on cessation of dust exposure

Rats were exposed by inhalation to coal mine dust, titanium dioxide, or quartz. The magnitude of the consequent inflammatory response was assessed by counting numbers and types of leukocytes in the bronchoalveolar lavage fluid. The magnitude of the inflammatory response reflected the toxicity of the dusts, with quartz eliciting the greatest recruitment of inflammatory leukocytes, coal mine dust less than quartz, and titanium dioxide eliciting no inflammation. To assess the persistence of the inflammation, groups of rats were maintained in room air for 30 or 60 days after cessation of dust exposure and then numbers of leukocytes were assessed. Bronchoalveolar leukocytes in rats exposed to coal mine dust were reduced after exposure, but in the quartz-exposed rats the numbers increased with time after exposure. The chemotactic responses of bronchoalveolar leukocytes from rats inhaling coal mine dust and quartz were reduced and remained so after a 30-day recovery period. Their reduced ability to chemotact did not fully prevent macrophages from leaving the bronchoalveolar region of dust-exposed rats. However, it is likely that the delayed removal of inflammatory leukocytes with the potential to injure the lung tissue may contribute to septal damage and so contribute to the pathogenesis of pneumoconiosis.

Effect of storage upon the toxicity of synfuel process waters to bacteria

Storage of synfuel process waters at 4 degrees C for 8 years appeared to reduce the toxicity of these waters to indicator bacteria. When these waters were mixed in the amount of 10 percent process waters to 90 percent sewage, heterotrophic bacteria grew which indicate that storage or aeration may improve the treatability of these waters.

Exposure-response relationships for coal mine dust and obstructive lung disease following enactment of the Federal Coal Mine Health and Safety Act of 1969

Underground U.S. coal miners were studied cross-sectionally for the association of respirable coal mine dust exposure with pulmonary function and symptoms of airways obstruction. The study group included 1,185 miners participating in Round 4 of the National Study of Coal Workers' Pneumoconiosis who had started mining in or after 1970 when comprehensive exposure regulations first came into effect. Quantitative estimates of cumulative exposure, derived using respirable dust measurements taken by the Mine Safety and Health Administration over the entire study period, were used in linear and logistic regression models on indicators of pulmonary function and chest symptoms while controlling for smoking status, pack-years, and other potential confounders. Statistically significant associations between log cumulative exposure and decrements in FVC, FEV1, and FEV1/FVC were observed. In logistic models, statistically significant associations of cumulative exposure with increasing prevalence of FEV1 and FEV1/FVC less than 80% predicted and symptoms including chronic phlegm, chronic bronchitis, breathlessness, wheeze, and wheeze with shortness of breath were found. It is concluded that exposures to respirable coal mine dust present in U.S. mines since 1970 continue to affect respiratory health in underground miners.

Relationship between weathered coal deposits and the etiology of Balkan endemic nephropathy

Field studies in epidemiology and environmental geochemistry in areas in Yugoslavia containing villages with a high incidence of Balkan endemic nephropathy (BEN), indicate a possible relationship between the presence of low-rank coal deposits and the etiology of BEN. Preliminary results from qualitative chemical analyses of drinking water from shallow farm wells indicate the presence of soluble polar aromatic and polynuclear aromatic hydrocarbons. These compounds may be derived from weathering of low-rank coals occurring in the vicinity of the endemic villages. All of the endemic villages are in alluvial valleys of tributaries to the Danube River. All except one of the clusters of endemic villages are located in the vicinity of known Pliocene age coals. Detailed sampling of the drinking waters and the nearby coals are being undertaken to identify a possible etiologic factor.

An epidemiological study of lung cancer in Xuan Wei County, China: current progress. Case-control study on lung cancer and cooking fuel

In Xuan Wei County, Yunnan Province, lung cancer mortality rates are among China's highest in males and females. Previous studies have shown a strong association of lung cancer mortality with air pollution from "smoky" coal combustion. In the present quantitative risk assessment of indoor air pollution study, the result strongly shows an obvious on-site exposure-response relationship between benzo[a]pyrene concentration in indoor air and lung cancer mortality and strongly supports the hypothesis that indoor air pollution is the main risk factor in inducing lung cancer in Xuan Wei County. In the present case-control study, the result shows that in females, the presence of lung cancer is statistically significantly associated with chronic bronchitis and family history of lung cancer. The results also suggest an association of lung cancer with duration of cooking food, but not with passive smoking. In males, the presence of lung cancer is associated with smoking, bronchitis, family history of lung cancer, and personal history of cooking food.

[An investigation of fluoride pollution caused by burning coal containing fluoride in Xiushan and Baojing]

This paper reports an investigation of contents of soluble fluoride in the environment and foods in Xiushan and Baojing. On the basis of measuring concentrations of soluble fluoride in drinking water, soil, coal, air, fly ash, maize, chilli, and other kinds of vegetables, it is first to expand the pathway of fluoride migrating from coal into human body is through pollution of air by fluoride contained in fly ash on burning of coal, and then via consumption of polluted maize by air. The significant correlation between both the concentrations of fluoride in maize and in fly ash is proved. It is suggested to select the concentration of fluoride in fly ash or in air as the quality index of indoor air and the control target to prevent fluorosis.

[Study of prevention technique of fluorosis caused by burning coal containing fluoride-reducing fluoride content of indoor air with the help of sesled range]

Effects of reducing fluoride content of indoor air by the Mushan improve coal range, and the heated bed designed and made by these authors are quantitatively evaluated in this paper. The result shows that only heated bed can be effective to prevent fluorosis caused by burning coal containing fluoride.

Antimutagenicity studies of chlorophyllin using the Salmonella arabinose-resistant assay system

Studies with the arabinose-resistant Salmonella forward mutation assay system were performed to determine the antimutagenic activity of chlorophyllin against the mutagenic activity of aflatoxin B1 (AFB1), 2-aminoanthracene (2AA), benzo[a]pyrene (BaP), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and solvent extracts of coal dust (CD), diesel emission particles (DE), airborne particles (AP), tobacco snuff (TS), black pepper (BP) and red wine (RW). Various concentrations of each chemical and complex mixture extract were assayed for mutagenic activity with and/or without S9 in a preincubation test. One concentration of each chemical and complex mixture extract was then tested with various concentrations of chlorophyllin. Results showed that chlorophyllin, at concentrations of 2.5 mg/plate or less, completely or almost completely inhibited the mutagenicity of 2AA, AFB1, BaP, MNNG and solvent extracts of CD, DE and RW. With concentrations from 1.25 to 5 mg/plate, chlorophyllin inhibited over 50% of the mutagenicity of AP, TS and BP extracts. These results further substantiate the antimutagenic efficacy of chlorophyllin against chemicals and complex mixtures.

[A hygienic basis for dosing the injection of coal flotation wastes into the soil as a fertilizer]

Hygienic regulations for the use of coal flotation wastes (CFW) as fertilizers were substantiated by studying the laws of migration of harmful ingredients of CFW from the fertilized soil to the contacting media. The safe doze of CFW to be used as a fertilizer was determined to be 3 g per 1 kg of soil (10 t/ha).

Assessment of potential biases in the application of MSHA respirable coal mine dust data to an epidemiologic study

Systematic errors in exposure data will result in biased estimates of the exposure-response relationship derived from epidemiologic analyses. Thus, adjustment of exposure data to account for identified errors may provide for a more accurate assessment of effect. In preparing to apply respirable coal mine dust exposure data collected by the Mine Safety and Health Administration (MSHA) to a study of the pulmonary status of underground coal miners, an assessment of potential systematic errors was undertaken. Potential errors stemming from adjustment of controls during sampling, concentration-dependent sampling, truncation of sampling results, identified sampling equipment problems, and a disproportionate number of low concentration samples in mine operator-collected samples were identified and evaluated. Methods to account for these errors and adjust mean exposures by mine, occupation, and year are given.

Goitrogens in food and water

Epidemiologic and experimental evidence reviewed in this article emphasizes the complex and multifactorial etiology of endemic goiter. The important role of iodine deficiency as an etiologic factor in endemic goiter is firmly established, but there is evidence that other environmental factors can play an equally important role in the pathogenesis of this condition. Chemical categories, sources, and sites of action of the various classes of naturally occurring goitrogens and antithyroid agents are reviewed in this article. Evidence of the presence of these compounds in foodstuffs and drinking water is discussed. Bacterial contamination of water supplies also appears to be important in the development of goiter. Microorganisms appear to intervene in the biosynthesis and degradation of organic goitrogenic pollutants or may induce thyroid growth-promoting activity in the host, or both. Malnutrition and poor socioeconomic conditions, as for iodine deficiency, enhance the action of environmental goitrogens. Thus, a coordinated multidisciplinary approach is essential to solving this public health problem.

Respirable dust exposures in U.S. surface coal mines (1982-1986)

Exposure of miners to respirable coal mine dust and to respirable quartz silica at surface coal mines in the United States during 1982-1986 were evaluated by job category using data collected by coal mine operators and Mine Safety and Health Administration (MSHA) inspectors. Average coal mine dust concentrations were usually well below the MSHA Permissible Exposure Limit (PEL) for all job categories, but at least 10% of the samples obtained from some coal preparation plant job areas and most drilling job areas had concentrations that exceeded the 2.0 mg/m3 limit. In contrast, a very high proportion of samples from surface mine driller areas exceeded the quartz PEL. Of all samples collected for highwall drill operators and helpers, 78% and 77%, respectively, were greater than the 0.1 mg/m3 quartz exposure limit (average concentrations were .32 and .36 mg/m3, respectively). Although MSHA compliance data may not be entirely adequate for assessing chronic exposure to quartz, these data and the results of other NIOSH studies nonetheless indicate excessive exposure to silica in a group of surface coal miners.

Mouse skin tumorigenicity studies of indoor coal and wood combustion emissions from homes of residents in Xuan Wei, China with high lung cancer mortality

The rural Xuan Wei County, Yunnan Province, China, has an unusually high lung cancer mortality rate that cannot be attributed to tobacco smoke or occupational exposure. The lung cancer rate is associated with 'smoky' coal, in contrast to wood or 'smokeless' coal burned in unventilated homes. This study was conducted to characterize and compare mouse skin tumorigenicity of the coal and the wood combustion emissions and to link the animal data to human lung cancer. Indoor air particles (less than 10 microns) were collected from a central commune where the lung cancer mortality rate is high and smoky coal is the major fuel used and also from a south-western commune where lung cancer mortality rate is low and where wood or smokeless coal are the major fuels used. The organic extracts of these indoor air particles from smoky coal, smokeless coal and wood combustion were analysed for polycyclic aromatic hydrocarbons and assayed for skin tumor initiation activity and complete carcinogenicity in SENCAR mice. The results showed that the organic extract of the emission particles from smoky coal combustion is the most active in tumor initiation among the three combustion emission samples followed by smokeless coal and then wood. The organic extract of the particles from smoky coal combustion was shown to be a potent complete carcinogen, whereas the wood extract was relatively inactive as a complete carcinogen. The extract of particles from the smokeless coal combustion was not tested for complete carcinogenicity because of inadequate supply. Eighty-eight percent of the mice treated with the smoky coal extract showed carcinomas, averaging 1.1 carcinomas per tumor-bearing mouse at the end of the 77 week study. These findings were in agreement with the epidemiological data, which showed that the Xuan Wei residents using smoky coal as a major fuel in homes had a high lung cancer mortality rate. This study demonstrates that the results of the tumorigenicity assays in mice were in agreement with human lung cancer data.

Pulmonary effects of ultrafine coal fly ash inhaled by guinea pigs

Guinea pigs were exposed to ultrafine coal fly ash produced in a laboratory furnace. The average mass median aerodynamic diameter and the average mass concentration of Illinois no. 6 fly ash produced in all exposure conditions were 0.21 microns and 5.8 mg/m3, respectively. In guinea pigs exposed to Illinois no. 6 fly ash, total lung capacity (TLC), vital capacity (VC), and diffusing capacity for carbon monoxide (DLco) were significantly reduced below the control values immediately, 2 h, and 8 h postexposure. The diffusing capacity was still 10% below the control 96 h after exposure. The total sulfate in the Illinois no. 6 fly ash as determined using ion chromatography is 1105 +/- 120 micrograms/m3. Animals exposed to the Montana lignite fly ash at comparable concentration and particle size did not show alteration in diffusing capacity. The data suggest that part of the sulfate present in the fly ash of Illinois no. 6 could be in the form of sulfuric acid and is responsible for the adverse effects observed in the exposed animals. The sulfuric acid in the fly ash of Montana lignite is neutralized by its high alkali content and produces no change in lung functions.

[The investigation of the total amount of fluoride intake with correlative dental fluorosis polluted by burn coal in the epidemic fluorosis districts]

By means of the investigation in the five different townships with contrasting of the others, the main sources of fluorosis were found from pollution of the coal smoke, the content and total amount of fluoride intake from the maize and capsicum were calculated to be 74.35-94.72% by drying of the heat of burn coal and increased with the total amount of fluoride intake. The clear doses of the prevalence rates of dental fluorosis, the mean output of urinary fluoride and the total amount of fluoride intake--response relationship, showing a semilogarithmic positive correlation between 8 and 15 years of age. At the age the prevalence rates of bad incomplete teeth and milk-teeth showed a linear correlation with the total amount of fluoride intake and the mean output of urinary fluoride respectively. And seven regression equations were calculated. The question concerning the epidemic fluorosis districts caused by burn coal was discussed. We suggest that sick districts can be affirmed on the basis of the total amount of fluoride intake, the prevalence rates of dental fluorosis, bad incomplete teeth, milk-teeth and the mean output of urinary fluoride between 8 and 15 years of age.

Subacute inhalation toxicity of a medium-boiling coal liquefaction product (154-378 degrees C) in the rat [Part III]

The short-term inhalation toxicity of a medium-boiling coal liquefaction product (CLP) was investigated in the rat. Groups of 5 male and 5 female Sprague-Dawley rats were exposed to CLP aerosols at 25 mg/m3 (low dose) or 100 mg/m3 (high dose) 6 h/d, 5 d/w, for 4 wk. The control group was exposed to filtered air while the positive control received diesel fuel aerosols at 100 mg/m3. Male rats exposed to high-dose CLP aerosols exhibited growth depression and increased hepatic aminopyrine demethylase activity compared to control animals. High-dose females had decreased hemoglobin content and hematocrit values. These biochemical and hematological effects were not observed in animals of either sex treated with the diesel fuel. No other biochemical and hematological changes were observed. Mild histological changes occurred in the liver and thyroid of rats treated with CLP and diesel fuel aerosols. Based on the data presented, inhalation of CLP aerosols resulted in toxicological effects that were similar to those caused by dermal exposure.

Factors associated with the development of progressive massive fibrosis in British coalminers: a case-control study

Possible associations between the incidence of progressive massive fibrosis (PMF) over periods of average length 11 years during 1963-80 and a range of explanatory variables, both environmental and medical, were examined in a study group of 4772 miners and ex-miners using case-control methods. Cases were members of the study group who developed PMF during the study period; controls were men who remained free of the disease. Cases and controls were matched on cumulative dust exposure to the start of the study period, colliery of employment, and whether or not employment before and during the study period had been at a single colliery only. Of 257 cases of PMF, 142 were matched to four controls each, 39 to three controls, 33 to two controls, and 31 to a single control only. Twelve cases could not be matched. Age and category of simple pneumoconiosis were each found to be associated with the incidence of PMF, confirming the results of many previous studies. Quetelet's index of body mass (a measure of weight, normalised for height) was found to differ considerably between cases and controls, cases tending to be lighter for their height. The difference did not vary significantly between three groups of collieries, defined by coal rank. Regression analysis confirmed the high level of statistical significance of the difference (p less than 0.001), allowing for the effects of age and prior category of simple pneumoconiosis. Of the environmental factors considered, an index of residence time of dust in the lungs was found to have the most statistically significant association with the incidence of PMF. The crudeness of the measure used, however, together with unreliability in estimates of early exposure to dust for some of the men studied, means that further work is necessary to investigate the magnitude and significance of this apparent association. In low and medium rank collieries there were large differences between the proportion of cases and controls showing a range of respiratory symptoms, cases consistently displaying a higher prevalence. In the high rank collieries of south Wales, however, symptoms occurred with equal frequency in cases and controls, the prevalence at these collieries being the same as among cases generally. Regression analysis (low and medium rank collieries only) showed that the presence of breathlessness was the symptom most strongly associated with the risk of attack of PMF, allowing for the effects of age and Quetelet's index.

Case-control study of hydrocarbon exposures in patients with renal cell carcinoma

A retrospective case-control study tested the hypothesis that exposure to hydrocarbon combustion products is associated with the development of renal cell carcinoma. One control per case, matched for sex, date of birth (within 5 years) and urologist, was chosen. Controls were patients who presented with hematuria and were shown not to have a urinary tract tumour. A total of 164 cases and 161 controls responded to mailed questionnaires and telephone interviews. Smoking more than 20 cigarettes per day was associated with the presence of metastatic renal cell carcinoma (p less than 0.001). Exposure to burning coal was associated with an increased relative risk of the disease but only when the exposure occurred between the ages of 10 and 24 years (p less than 0.05). Dose-response relations were demonstrated for intensity of exposure (p less than 0.025) and duration of occupational exposure (p less than 0.05). The distribution of latent periods from first exposure to diagnosis was bimodal, with one mode at 21 to 30 years and another at 41 to 50 years. Occupational exposure to tar or pitch or both was also associated with an increased relative risk of renal cell carcinoma (p less than 0.05).

[Semi-malignant pitch-acanthoma on the hand of a coke oven worker]

We experienced a case of pitch-acanthoma which had developed on the hand of a coke worker after 15 years from his retirement. The patient was a 75-year-old male, who had worked mainly as a coke-oven worker for 24 years. In the spring of 1988, after 15 years from his retirement, he noticed a small nodule on the dorsal aspect of his right hand. He visited our clinic on June 1988 because the nodule was rapidly growing larger. The diagnosis of pitch-acanthoma was obvious from his occupational history and the characteristic poikilodermatous outlook of his skin. The tumor was removed surgically. Histological examination showed hyperkeratosis and acanthosis with horn-pearl formation. Moreover, a pack of atypical cells was observed within the lesion, suggesting an early malignant change. The patient was heavily exposed to a tar-gas-containing atmosphere in his workplace for quite a long period. As tar or pitch remains within the skin in spite of careful cleansing, workers in this atmosphere have a relatively high risk of developing skin cancer. Our present case shows that such malignant change can occur after long years and we would emphasize the necessity of a long term follow-up, perhaps throughout the lifetime of these workers.

Effectiveness of the United Steel Workers of America Coke Oven Intervention Program

This paper describes the implementation and evaluation of the Coke Oven Intervention Program developed jointly by the United Steel Workers of America and the University of Pittsburgh. The program was offered on four occasions at each of seven coke oven plants over a 2-year period. Participants were compared with nonparticipating co-workers and controls from matched plants on knowledge of the Coke Oven Standard and workplace behaviors. Few baseline differences were found among participants, nonparticipants, and controls. Participants improved significantly as a result of the program, with those attending multiple programs accruing the greatest benefits. Panel controls interviewed on six occasions throughout the 2-year period showed little improvement. Reasons for and implications of the effectiveness of the program are discussed.

Effects of occupational exposure and smoking on respiratory symptomatology and PFT in healthy panelists and COPD patients

A panel of 377 healthy adults and 920 COPD patients aged 30-65 years, is annually interviewed (ATS-NHLI health questionnaire) and performs pulmonary function test (PFT), which includes: FVC, FEV1, FEV1/FVC, PEF, FEF50 and FEF75. Baseline data analysis showed a more significant excess in respiratory symptoms (8.8% to 21.4%) and lower PFT (2.4% to 8.0%) among patients occupationally exposed to dust, than among healthy exposed panelists (-0.7% to 7.7% excess symptomatology and -0.3 to 5.8% lower PFT). Among patients a significant correlation between PFT and degree of occupational dust exposure was found. Significantly lower FEV1/FVC and excess in respiratory symptoms (with relative risks of 2.47-16.38) was present in healthy smokers vs. non smokers as compared with COPD patients.

A retrospective cohort mortality study on workers of two thermoelectric power plants: fourteen-year follow-up results

Although many studies have been performed to evaluate the environmental impact of coal energy production, few studies are available on the health risk for the people working in coal power plants. A retrospective cohort study was performed on the workers of two power plants near Venice (which use coal since 1968) in order to test the association between exposure to coal dust and ashes and mortality for all causes, all cancers, and respiratory and digestive cancer. One thousand three hundred seven male workers were followed up from 1968 to 1984. During this period 41 workers died; causes of death were collected from the local Mortality Registers and/or from the Hospital Records. The observed mortality of the study cohort was compared with the mortality expected from the Italian death rates in the same period. No Standardized Mortality Ratio (SMR) was found in excess in the working cohort with respect to the standard population for any of the investigated effects.

Detection of reactive free radicals in fresh coal mine dust and their implication for pulmonary injury

Freshly ground and aged anthracite and bituminous coal samples were investigated by electron spin resonance (ESR) spectroscopy to detect the presence, concentration and reactivity of free radicals. Freshly ground anthracite coal produced greater concentration of free radicals than the bituminous coal, and the radical reactivity was also greater for the anthracite. The reactivity of the newly produced free radicals in the anthracite dust correlated with the dust's toxicity. Furthermore, similar coal-based free radicals were detected in the lung tissue of autopsied coal miners, suggestive of persistent reactivity by the embedded coal dust leading to the progressive disease process. Results of the studies on the severity of coal workers' pneumoconiosis (CWP) and free radical concentration in lung tissue support this hypothesis.

A multistage approach to the cohort analysis of lifetime lung cancer risk among steelworkers exposed to coke oven emissions

A cohort analysis was performed to predict the lifetime lung cancer risk to a US or Canadian nonwhite male steelworker exposed to coke oven emissions. The procedure employed required that the lung cancer mortality (used for risk assessment) be estimated by addition of the excess to the background rates. The age-specific excess rates were obtained following selection of the proper excess risk function as implied by the multistage theory of carcinogenesis. A quantitative approach based on model fitting was used for selection of the excess risk function. The results show no evidence that coke oven emissions have a late stage carcinogenic effect. The indication that the agent acts as an initiator is moderate to weak. The number of carcinogenic stages involved was estimated to be four. Based on the assumption that exposure was set at a high concentration for 40 years with a starting age of 20 years, it was estimated that the lifetime risk through age 85+ years for a hypothetical US or Canadian nonwhite male oven worker could be as high as 0.40. This represents a 15-fold increase of the baseline risk.

Pulmonary and hepatic glutathione levels, glutathione shuttle enzymes and lipid peroxidation in rats exposed intratracheally to coal fly ash

Fly ash and fly ash residue increased the formation of conjugated dienes and the levels of oxidized glutathione (GSSG) and reduced the levels of reduced glutathione (GSH) in lung and liver whereas fly ash extract administration had no effect on the formation of conjugated dienes and glutathione levels in lung and liver. Fly ash and fly ash residue reduced the activity of glutathione reductase both in lung and liver but did not alter the activity of glutathione peroxidase. Fly ash and fly ash extract significantly increased glucose-6-phosphate dehydrogenase activity in lung whereas in liver, fly ash and fly ash residue reduced the activity of glucose-6-phosphate dehydrogenase. Fly ash residue did not alter the activity of glucose-6-phosphate dehydrogenase in lung whereas fly ash extract was not effective in liver.

Indoor air pollution of coal fumes as a risk factor of stroke, Shanghai

A cohort of 957 male persons in Shanghai has been followed up for 12 years after they entered a screening program for coronary heart disease and stroke. During the period of study, 24 of the subjects who had no previous history of heart disease and stroke died from stroke. Risk factors for stroke were analyzed by the Cox proportional hazards model. Coal fumes were found to be an independent risk factor for stroke in addition to diastolic blood pressure, age, and cigarette smoking.