Cancer mortality in U.S. counties with hazardous waste sites and ground water pollution

Since the late 1950s, more than 750 million tons of toxic chemical wastes have been discarded in an estimated 30,000 to 50,000 hazardous waste sites (HWSs). Uncontrolled discarding of chemical wastes creates the potential for risks to human health. Utilizing the National Priorities Listing (NPL) of hazardous waste sites developed by the United States Environmental Protection Agency (EPA), this study identified 593 waste sites in 339 U.S. counties in 49 states with analytical evidence of contaminated ground drinking water providing a sole source water supply. For each identified county, age-adjusted, site-specific cancer mortality rates for 13 major sites for the decade 1970-1979, for white males and females, were extracted from U.S. Cancer Mortality and Trends 1950-1979. Also, HWS and non-HWS counties that showed excess numbers of deaths were enumerated for each cancer selected. Significant associations (p less than .002) between excess deaths and all HWS counties were shown for cancers of the lung, bladder, esophagus, stomach, large intestine, and rectum for white males; and for cancers of the lung, breast, bladder, stomach, large intestine, and rectum for white females when compared to all non-HWS counties. There were no consistent geographical patterns that suggested a broad distribution of gastrointestinal cancers associated with HWSs throughout the United States, although we did identify a cluster of excess gastrointestinal cancers in counties within states located in EPA Region 3 (Delaware, Maryland, Pennsylvania, Virginia, West Virginia).(ABSTRACT TRUNCATED AT 250 WORDS)     

Cancer mortality in four northern wheat-producing states

Chlorophenoxy herbicides are used both in cereal grain agriculture and in nonagricultural settings such as right-of-ways, lawns, and parks. Minnesota, North Dakota, South Dakota, and Montana grow most of the spring and durum wheat produced in the United States. More than 90% of spring and durum wheat is treated with chlorophenoxy herbicides, in contrast to treatment of approximately 30% of winter wheat. In this ecologic study I used wheat acreage as a surrogate for exposure to chlorophenoxy herbicides. I investigated the association of chlorophenoxy herbicides with cancer mortality during 1980-1989 for selected counties based on level of agriculture ([greater and equal to] 20%) and rural population ([greater and equal to] 50%). Age-standardized cancer mortality rates were determined for grouped counties based on tertiles of wheat acreage per county or for individual counties for frequently occurring cancers. The cancer sites that showed positive trends of increasing cancer mortality with increasing wheat acreage were esophagus, stomach, rectum, pancreas, larynx, prostate, kidney and ureter, brain, thyroid, bone, and all cancers (men) and oral cavity and tongue, esophagus, stomach, liver and gall bladder and bile ducts, pancreas, cervix, ovary, bladder, and other urinary organs, and all cancers (women). Rare cancers in men and women and cancers in boys and girls were studied by comparing counties above and below the median of wheat acreage per county. There was increased mortality for cancer of the nose and eye in both men and women, brain and leukemia in both boys and girls, and all cancers in boys. These results suggest an association between cancer mortality and wheat acreage in counties of these four states.     

Environmental carcinogen releases and lung cancer mortality in rural-urban areas of the United States

Purpose: Environmental hazards are unevenly distributed across communities and populations; however, little is known about the distribution of environmental carcinogenic pollutants and lung cancer risk across populations defined by race, sex, and rural‐urban setting. Methods: We used the Toxics Release Inventory (TRI) database to conduct an ecological study at the county level (a total of 3,141 counties). Multiple linear regressions were used to assess the associations of carcinogenic discharges from TRI sites and lung cancer mortality rates at the county level in the United States during the years 1990 through 2007. Findings: We observed an excess risk of population lung cancer mortality associated with higher amounts of environmental carcinogen releases from TRI facilities in both males and females, and in both whites and African Americans. The strength of these associations tended to be stronger in African Americans. A significant dose‐response relationship was observed for the total volume of carcinogen releases or carcinogen releases to the air, but not releases to water. These associations appeared to be present within nonmetropolitan counties but not metropolitan counties, and to be concentrated in certain urban‐rural county typologies. Conclusions: Our results suggest that exposure to higher carcinogen releases from industrial or chemical facilities in rural areas may increase the risk of lung cancer mortality. Our findings add to the evidence for undertaking prudent efforts to limit the release of carcinogenic chemicals into the environment.     

Patterns of milk consumption and risk of cancer

The reported milk consumption habits of 3,334 cancer patients and 1,300 comparable control subjects seen at Roswell Park Memorial Institute were studied. The cancer patient group included persons diagnosed with cancers of the oral cavity, stomach, colon, rectum, lung, breast, uterus, cervix, prostate, or bladder. Data were obtained by means of a standardized admissions questionnaire. As a group, control patients were more likely to report never drinking whole milk; cancer patients more often reported frequent consumption of whole milk. Relative risks of different patterns of milk consumption for specific cancer diagnoses, adjusted for sex, age, smoking history, education, and county of residence, were calculated with multiple logistic regression analysis. Elevated risks for frequent consumption of whole milk relative to not drinking milk were observed for cancers of the oral cavity, stomach, colon, rectum, lung, bladder, breast, and cervix. Reduced risks for frequent consumption of 2% milk relative to not drinking milk were observed for cancers of the oral cavity, stomach, rectum, lung, and cervix. Preference for exclusive consumption of reduced-fat milk was linked to significant risk reduction for oral and cervical cancers, and drinking only whole milk was linked to significant risk increases for cancers of the oral cavity, stomach, rectum, lung, and breast. Some associations were observed for a computed index of milk fat intake, but the overall pattern of effects was not fully explained by variations in fat content. The effects observed for some sites may be confounded by other dietary or nondietary correlates of risk.     

Antioxidant status and cancer mortality in China.

Sex-specific mortality rates for selected cancer sites (including oesophagus, stomach, liver, lung, colorectum, breast and cervix) and a variety of biochemical indicators of antioxidant status, enzyme activity and oxidative stress (including plasma levels of beta-carotene, alpha-tocopherol, ascorbic acid, selenium, glutathione peroxidase, catalase, superoxide dismutase, iron, copper, zinc, total cholesterol and lipid peroxide) were examined in an ecological study of 65 mostly rural counties in the People's Republic of China. The wide range of both mortality rates and biochemical values and the measurement of a comprehensive set of biochemical indicators permitted both simple correlational and multivariate analyses of the joint and relative effects of each factor on site-specific cancer mortality. Plasma levels of dietary antioxidants were consistently negatively correlated with cancer mortality rates. Ascorbic acid was most strongly negatively associated with most cancers and selenium with oesophageal and stomach cancers. beta-carotene was found to have a protective effect independent of retinol, particularly for stomach cancer.     

Geographical differences of cancer incidence in Costa Rica in relation to environmental and occupational pesticide exposure.

BACKGROUND: This study describes geographical differences in cancer incidence in Costa Rica, and investigates if some of these differences may be related to pesticides. METHODS: Data were combined from the cancer registry (1981-1993), the 1984 population census, the 1984 agricultural census, and a national pesticide data set. The 81 counties of Costa Rica were the units for the ecological analyses. Adjacent counties were grouped into 14 regions (3 urban and 11 rural) with relatively similar socioeconomic characteristics. County indices for population density and agricultural variables were constructed and categorized. Differences across regions and categories were assessed by comparing observed numbers of incident cases to expected values derived from national rates. Within the tertile of most rural counties, rate ratios between categories of high and low pesticide use were calculated. RESULTS: In urban regions, excesses were observed for lung, colorectal, breast, uterus, ovary, prostate, testis, kidney, and bladder cancers; and in rural regions for gastric, cervical, penile, and skin cancers. Skin cancers (lip, melanoma, non-melanocytic skin and penile cancer) occurred in excess in coffee growing areas with extensive use of paraquat and lead arsenate. In the most rural subset, heavy pesticide use was associated with an increase of cancer incidence overall and at a considerable number of specific sites, including lung cancer (relative risk [RR] 2.0 for men and 2.6 for women) and all female hormone-related cancers (RR between 1.3 and 1.8). CONCLUSIONS: Regions and populations at high risk for specific cancers were identified. Several hypotheses for associations between pesticides and cancer emerged. The findings call for studies at the individual level.     

Bladder cancer mortality in New Jersey counties, and relationship with selected environmental variables

Age-adjusted mortality rates for bladder cancer were calculated for the 21 New Jersey (NJ) counties (USA) during the period 1968-1977, and compared with the period 1950-1969, with the Surveillance, Epidemiology and End Results (SEER) survey and with cancer mortality in the US 1973-1977. The county rates were also correlated with: the rates of low birth weight, birth defects, infant mortality; chemical waste disposal sites; annual per capital income; per cent of the population working in the chemical industries; density of population and urbanization indices of 21 NJ counties. Age-adjusted bladder cancer mortality rates in 95% of NJ counties were higher than national and SEER area rates. The overall NJ State rates for four subgroup populations were highly significantly (p less than 0.001) greater than the national rates. There was a statistically significant correlation between bladder and lung cancer mortality among females in 21 NJ counties which may suggest a common risk factor--namely cigarette smoking. There was no such correlation between bladder and lung cancer mortality among males. There was a statistically significant association between bladder cancer mortality in individual counties and the percentage of the adult population working in the chemical industries.     

Mortality and cancer experience of Quebec aluminum reduction plant workers. Part 3: monitoring the mortality of workers first employed after January 1, 1950

OBJECTIVE: To monitor changes over time in mortality of workers first employed in Quebec aluminum smelters after January 1, 1950 (1951-one cohort). METHODS: Mortality of cohorts by decade of hire was compared with Quebec and same plant experience before 1950 (1951). RESULTS: Chronic obstructive pulmonary disease and respiratory cancer (one cohort each) mortality were statistically in excess. In the combined cohorts, standardized mortality ratios exceeded 110 for cancers of esophagus, rectum, and rectosigmoid junction, pancreas, larynx, lung, non-Hodgkin lymphoma, cerebrovascular disease, and asthma. These findings essentially mirrored the experience of pre-1950 workers. There was a significant downward trend in mortality from all causes, lung and bladder cancer. CONCLUSIONS: Statistically significant improvements were found in mortality from all causes combined, from cancer and from cancer of the lung and bladder. Slightly increased mortality continues from certain other causes.     

Marital status and cancer risk in Italy

BACKGROUND: Marital status has long been related to cancer incidence and mortality rates. However, only few analytical studies have been conducted on this issue considering known or potential confounding factors. METHODS: We systematically examined the relation between marital status and cancer risk using data from a network of case-control studies conducted between 1983 and 2001, including a total of 17,976 incident cases with the following cancer sites: oral cavity and pharynx, esophagus, stomach, colon, rectum, liver, gallbladder, pancreas, larynx, breast, endometrium, ovary, prostate, bladder, kidney, thyroid, Hodgkin's disease, non-Hodgkin's lymphomas, multiple myelomas, and sarcomas. Controls were 15,345 patients admitted to the hospital for non-neoplastic conditions. RESULTS: As compared to married subjects, never married ones were at significantly increased risk of oral cavity and pharyngeal cancers and at reduced risk of cancer of the colon, liver, bladder, kidney, and thyroid. However, for other cancer sites considered, most odds ratios were close to unity. Likewise, there was no consistent excess risk for divorced or widowed subjects. CONCLUSIONS: Despite some significant associations, our study suggests that marital status is not materially associated with cancer risk. Thus, the evidence that married subjects are at lower risk of several other major diseases may not be applicable to cancer.     

2013年青海省城市、农村、牧区不同地区特征恶性肿瘤死亡分析

目的 分析2013年青海省肿瘤登记地区恶性肿瘤死亡情况,为青海省肿瘤防治提供依据。方法 2016年青海省6个登记地区上报2013年恶性肿瘤死亡资料,根据全国肿瘤登记中心对肿瘤登记数据质量要求,对数据质量较好的3个地区（西宁市区、湟中县、海南州）的资料进行统计分析。结果 2013年纳入分析的3个肿瘤登记地区,恶性肿瘤死亡率为114.53/10 万（男性144.78/10万,女性84.21/10万）,中标率为110.44/10 万。死亡率前十位依次是胃癌、肝癌、肺癌、食管癌、结直肠癌、子宫颈癌、女性乳腺癌、胰腺癌、子宫体癌和脑瘤。结论 胃癌、肝癌、肺癌、子宫颈癌、食管癌是青海省肿瘤登记地区最多发的肿瘤,应作为防治工作的重点。     

Diet quality and subsequent cancer incidence and mortality in a prospective cohort of women

BACKGROUND: We have previously reported on the utility of the Recommended Foods Score (RFS), a measure of overall diet quality, in detecting associations between diet and mortality in a cohort of older women. Using additional follow-up, we have now extended our analysis to detailed studies of associations between RFS and the mortality and incidence from common cancers. METHODS: The RFS, the sum of 23 recommended food items consumed at least weekly, was computed from a 62-item food frequency questionnaire completed at baseline by 42 254 women with a mean age of 61 years. Multivariate adjusted relative risk (RR) of cancer mortality and incidence of the cancers for which we were able to obtain data in relation to quartiles of RFS were examined using proportional hazards regression analyses after a median follow-up period of 9.5 years. RESULTS: We observed that RFS was inversely associated with total mortality (RR = 0.8; P < 0.001) cancer mortality (RR = 0.74; P < 0.001) as well as mortality from cancers of the breast (RR = 0.75; P < 0.06), colon/rectum (RR = 0.49; P < 0.01) and lung (RR = 0.54; P < 0.001). The risk of incident lung cancer (RR = 0.62; P < 0.001) was reduced in women in the highest vs the lowest quartile of RFS; for incident cancers of the breast, colorectum, endometrium, ovaries, and bladder, there was no RFS association. CONCLUSION: A dietary pattern reflecting a higher RFS was associated with decreased overall mortality in women, specifically cancers of the lung, colon/rectum, and to a lesser extent breast. Incidence was only decreased for lung cancers. These observations are consistent with the hypothesis that a high RFS dietary pattern, or associated lifestyle factors, might affect cancer progression and survival.     

Incidence and mortality due to cancer in Navarre, 1998-2002. Trends in the last 30 years

Between 1998-2002, 16,952 new cases of cancer were registered in Navarre. In men, the most frequently diagnosed cancers were in the following order: prostate, lung, colon and rectum, bladder and stomach, which accounted for 63.2%. In women, the sites were breast, colon and rectum, corpus uteri, stomach and ovary, which accounted for 57.6% of the cases. In the same period, 1998-2002, 4,127 men and 2,470 women died from cancer. Sixty percent of all deaths due to malign tumours in men were due to cancer of the lung, prostate, colon and rectum, stomach and bladder. In women this was due to cancers of colon and rectum, breast, stomach, pancreas and lung, which accounted for 49% of the cases. In men in Navarre there has been an increase in the incidence rates of cancer of the prostate, kidney and non-Hodgkin lymphoma. Avoidable cancers such as those related to smoking (lung, oral cavity and pharynx or pancreas) continue to rise, and represent a greater global risk of dying from cancer in the latest period studied than in the decades of the 1970s and 1980s. From 1995 up to the present, mortality due to cancer has moved from occupying the second place to become the first cause of death among men in Navarre. The global risk of death due to cancer in men is now equal to the first period studied, 1975-1977. Amongst women the global risk of death due to cancer fell by 25% between 1975 and 2002, basically at the cost of breast and stomach cancer. Tumours related to smoking increased both in mortality and in incidence and appear as a significant health problem amongst women in Navarre. Breast cancer has increased in incidence, with lower mortality figures than those of the first period 1975-1977. Invasive cancer of the cervix remains at very low rates in comparison with many European countries, including Spain. In both sexes colorectal and skin cancer has increased, while the incidence and mortality of stomach cancer continues to fall.     

中国城乡11市县常见恶性肿瘤发病趋势分析

目的 探讨中国恶性肿瘤发病特点及时间趋势.方法 采用中国城乡11个市县肿瘤登记处的1988-2002年资料进行统计与分析,描述恶性肿瘤发病现状,研究其时间趋势与发病特点.结果 11个市县肿瘤登记处覆盖地区15年内新发恶性肿瘤695 050例,粗发病率为215.50/10万,世界标准人口调整发病率为170.97/10万.主要恶性肿瘤发病率排序依次为肺癌、胃癌、肝癌、食管癌、乳腺癌、结肠癌、直肠癌、胰腺癌、膀胱癌、白血病.16种主要恶性肿瘤占全部的85.56%.1988-2002年恶性肿瘤合并的粗发病率呈较快上升趋势.按部位分析,增幅最大的是前列腺癌(185.48%),其次为胆囊癌、乳腺癌、结肠癌等.发病率下降幅度最大的是宫颈癌(17.00%),其次为食管癌、胃癌、鼻咽癌.结论 中国11个市县1988-2002年恶性肿瘤总的粗发病率呈上升趋势,调整年龄因素后变化不明显.胰腺癌、膀胱癌、白血病已进入前10位,成为常见恶性肿瘤.前列腺癌和胆囊癌发病率虽然较低,但是增长幅度最大.     

Cigarette smoking and cancer: intensity patterns in the alpha-tocopherol, beta-carotene cancer prevention study in Finnish men

Relative risks for lung and bladder cancers by smoking intensity level off at more than 15-20 cigarettes per day. A three-parameter excess relative risk model in pack-years and intensity quantified this leveling (Lubin et al., Am J Epidemiol 2007;166:479-89). Above 15-20 cigarettes per day was an "inverse exposure rate" effect whereby, for equal pack-years, the excess relative risk/pack-year decreased with increasing intensity; that is, smoking at a lower intensity for a longer duration was more deleterious than smoking at a higher intensity for a shorter duration. After adjustment for pack-years, intensity effects were quantitatively homogeneous across multiple case-control studies of lung, bladder, oral cavity, pancreas, and esophagus cancers. The authors extended those analyses to examine intensity patterns for incident bladder, esophagus, kidney, larynx, liver, lung, oropharynx, and pancreas cancers by using data from a single prospective cohort in Finland, the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, with follow-up from enrollment, which occurred between 1985 and 1988, through April 2004. At more than 10 cigarettes per day, they found an inverse exposure rate pattern for each cancer site. After adjustment for pack-years, intensity effects were quantitatively homogeneous across the diverse cancer sites and homogeneous with intensity effects from the prior analysis of multiple studies. Consistency of intensity patterns suggested a general phenomenon and may provide clues to the molecular basis of smoking-related cancer risk.     

Respiratory organs cancer mortality in New Jersey counties and the relationship with selected demographic and environmental variables

The state of New Jersey (N.J.) has been thought to have an unusually high overall cancer mortality rate; this assumption has been based on national 1950–1969 mortality data for N.J. counties. This study presents an analysis of more recent rates of respiratory cancer mortality in 21 N.J. counties during 1968–1977, a comparison with the 1950–1969 rates, and associations between current respiratory cancer mortality rates and selected demographic and environmental variables. Age-adjusted mortality rates for cancer of respiratory organs were calculated for the N.J. counties during the period 1968–1977 and compared with the period 1950–1969, with the Surveillance, Epidemiology, and End Results (SEER) survey, and with cancer mortality in the United States, 1973–1977. The county rates were also correlated with chemical toxic-waste disposal sites (CTWDS), annual per capita income, percentage of the population employed in chemical industries, the density of population, and the urbanization index of each of 21 N.J. counties. The lung, bronchus, trachea, and pleura cancer mortality rates among white and nonwhite males and females in N.J. were substantially higher than the national rates during the period 1950–1969. In more recent years, the increases in U.S. mortality rates for lung, bronchus, trachea, and pleura cancers were significantly greater (P < 0.01) than those found in most of the 21 N.J. counties. As a consequence, the national rates are now more comparable to N.J. rates. Although the gaps between N.J. and the United States in these rates have narrowed, the observed number of laryngeal and lung cancer deaths remained significantly higher (P < 0.01 to P < 0.0001) than expected cancer deaths, based on U.S. rates, among one or more subgroup populations (white and nonwhite males and females) in several N.J. counties. Among white men in Middlesex, Camden, Burlington, and Ocean counties, the observed number of deaths for lung cancer was found to be significantly (P < 0.0001) greater than the expected number of deaths. In Hudson county observed deaths from both laryngeal and lung cancer among white men were significantly greater than the expected number of deaths from these cancers (P < 0.0001). Statistically significant and positive correlations were found between laryngeal cancer mortality and CTWDS, urbanization index, and population density. Lung cancer mortality also correlated significantly with CTWDS in N.J. Both larynx and lung cancer mortality showed significant and consistent negative correlations with annual per capita-income in N.J. Some of the implications of the study findings are discussed and recommendations made for future investigations.     

The residential radon-lung cancer association in U.S. counties: a commentary

There is little doubt that underground miners exposed to radon and its progeny have increased rates of lung cancer. Residential radon exposures should carry a possibly smaller risk of increased cancer. When it became possible to collect radon data in a large number of U.S. homes and the data were aggregated by counties, the apparent association with lung cancer was a negative one, even when many other variables were taken into account. Residential radon levels are higher in suburban residences leading to a negative association with population density. Population density is strongly positively associated with lung cancer. It follows that aggregate residential radon and lung cancer rates should be negatively associated for reasons having nothing to do with the possibility of radon being carcinogenic to the lung. A second problem presented by the data is the one of sampling bias since the county lung cancer data are from the whole county population, but only a few residences are tested. Examples of other inherent associations in environmental epidemiology are cited. One strategy is to study areas of the same population density but with radon exposure gradients. This is approximated by choice of rural high radon states. Counties in such states have weak and inconsistent associations between radon and lung cancer, some of which are positive. I conclude that counties are generally inappropriate units for study of radon and lung cancer associations.     

Cancer mortality in U.S. counties with chemical industries.

Geographic analysis of U. S. cancer mortality, 1950–1969, revealed excess rates for bladder, lung, liver, and certain other cancers among males in 139 counties where the chemical industry is most highly concentrated. The correlation could not be explained by confounding variables such as urbanization, socioeconomic class, or employment in nonchemical industries. If the excess cancer mortality in these areas is due to industrial exposures, the actual risk of cancer among certain chemical workers must be very high. The correlation was limited to counties associated with specific categories of the chemical industry; many involve known occupational hazards, while others suggest new leads to chemically induced cancer in man.     

Cancer mortality among workers in abattoirs and meatpacking plants: An update

Workers in abattoirs and meatpacking plants have potential for exposure to bovine leukemia virus (BLV) and bovine papilloma viruses (BPV), which are oncogenic in cattle. These workers also have increased exposure to human papilloma viruses (HPV) and certain chemical carcinogens. We investigated whether such a group showed increased risk of cancers. We report mortality results after an additional 9-year follow-up of a previously studied group of 5,522 workers in abattoirs and 4,589 workers in meatpacking plants. Excess risk of all cancers combined, cancers of the lung, buccal cavity and pharynx, esophagus, colon, bladder, kidney, and bone was observed. Since factors such as tobacco smoking, alcohol, and diet, which have known associations with some of these cancers, were not taken into account, the significance of these findings is not known, except for lung cancer, for which occupational factors are probably involved. Because some of these findings have been consistently reported before, studies that will control for confounding factors as well are now urgently needed.     

Correlates of liver cancer mortality in China

To provide clues to the causes of liver cancer in China, we studied the correlation of certain dietary and biochemical markers with liver cancer mortality across 65 Chinese counties. Mortality rates were significantly linked to the county-wide prevalence of hepatitis-B surface antigen positivity. Rates were also higher in counties with high plasma levels of total cholesterol and high consumption of liquor, rapeseed oil, and mouldy corn, while inverse associations were observed for wheat consumption. All of the observed associations, except those with cholesterol and rapeseed oil, were more pronounced in men than in women. No significant correlations with liver cancer mortality were found for consumption of several other foods; plasma levels of retinol, beta-carotene, alpha-tocopherol, selenium, zinc and ferritin; or urine levels of aflatoxin B1. Although causal inferences cannot be derived, this ecological study suggests that chronic infection with hepatitis-B virus contributes to the substantial variation in liver cancer mortality in China, and provides leads for further studies into the role of dietary and nutritional determinants.     

Mortality and cancer experience of Quebec aluminum reduction plant workers. Part 2: mortality of three cohorts hired on or before january 1, 1951

OBJECTIVE: To describe the mortality of Quebec aluminum smelter workers employed before 1951. METHODS: The mortality of 5,977 men hired at three plants on or before January 1, 1951 was compared with that of Quebec men. Relationships to benzo[a]pyrene, benzene-soluble material, and smoking were examined. RESULTS: Statistically significant causes of death were lung cancer (three plants); bladder cancer; chronic obstructive lung disease (two plants each); cancers of the stomach, digestive system unspecified, rectum and rectosigmoid, pancreas, and larynx; Alzheimer's disease (one plant); and cerebrovascular disease (one plant). Not significant increases were also observed. CONCLUSIONS: Mortality from cancer of the lung and bladder and chronic obstructive pulmonary disease are related to exposure in S?derberg smelters. The cause of increased stomach cancer mortality is unclear. Excess mortality from some other diseases may be explained by factors other than coal tar pitch volatiles exposure.