Gösta Axelsson

Magnesium in drinking water in relation to morbidity and mortality from acute myocardial infarction.

We investigated the importance of magnesium and calcium in drinking water in relation to morbidity and mortality from acute myocardial infarction. Cases were men and women 50-74 years of age living in 18 Swedish municipalities who had suffered an acute myocardial infarction some time between October 1, 1994, and June 30, 1996. Controls were randomly selected from the same study base. We interviewed the surviving cases (N = 823) and controls (N = 853), focusing on risk factors for acute myocardial infarction. We collected individual data on drinking water levels of magnesium and calcium. We classified subjects by quartile of water magnesium or calcium levels. The total number of cases was similar in the four quartiles. The risk of death was 7.6% (95% confidence interval = 2.1-13.1) lower in the quartile with high magnesium levels (> or = 8.3 mg/liter). The odds ratio for death from acute myocardial infarction in relation to water magnesium was 0.64 (95% confidence interval = 0.42-0.97) for the highest quartile relative to the three lower ones. Multivariate analyses showed that other risk factors were not important confounders. For calcium, this study was inconclusive. The data suggest that magnesium in drinking water is associated with lower mortality from acute myocardial infarction, but not with the total incidence.

Magnesium and calcium in drinking water and death from acute myocardial infarction in women.

A relation between water hardness and cardiovascular death has been shown in previous studies. In this case-control study, we investigated the levels of magnesium and calcium in drinking water and death from acute myocardial infarction among women. The study population encompassed 16 municipalities in southern Sweden. Cases were women who had died from acute myocardial infarction between the ages of 50 and 69 years during 1982-1993 (N = 378), and controls were women who had died from cancer (N = 1,368). We obtained magnesium and calcium concentrations of the individual water sources. We divided the subjects into quartiles and found that odds ratios (ORs) were lower at higher levels of both magnesium and calcium. For the quartile with the highest magnesium levels (> or =9.9 mg/liter), the OR adjusted for age and calcium was 0.70 (95% confidence interval = 0.50-0.99). For calcium, the adjusted OR for the quartile with the highest level (> or =70 mg/liter) was 0.66 (95% confidence interval = 0.47-0.94). The results suggest that magnesium and calcium in drinking water are important protective factors for death from acute myocardial infarction among women.

Pregnancy outcome of personnel in Swedish biomedical research laboratories.

Possible hazardous effects of laboratory work on the reproduction outcomes of female laboratory personnel in Sweden from 1990 to 1994 were investigated in a questionnaire-based study (n = 1052) by comparison with personnel in non-laboratory departments. The individual woman constituted the primary sampling unit, with her pregnancies defined as the unit of analysis. Allowance for dependence between different pregnancies of the same woman was considered by applying random effect models. With regard to spontaneous abortions, no elevated odds ratio was found for laboratory work in general, but an odds ratio of 2.3 and a 95% confidence interval of 0.9 to 5.9 (n = 856) was connected to working with chloroform. The odds ratio for large for gestational age infants in association with the mothers laboratory work was 1.9 (confidence interval, 0.7 to 5.2). The result with regard to spontaneous abortion partly supports previously reported increased risks of miscarriage related to laboratory work with solvents.

Mortality and cancer incidence in biomedical laboratory personnel in Sweden.

BACKGROUND The work in biomedical laboratories is associated with exposure to a mixture of known and potential chemical carcinogens, mutagens, and teratogens. Previous studies have suggested an excess of brain tumors and hematopoietic system malignancies as well as breast cancers in women. METHODS This retrospective cohort study investigated the standardized mortality ratio (SMR) and the standardized incidence ratio (SIR) for cancer in biomedical research laboratory personnel in Swedish universities 1970-1992. The cohort comprised 5,035 laboratory and, as an internal reference group, 2,923 nonlaboratory employees. RESULTS The overall death rate was lower in both groups than in the general population. The SIR for brain tumors among male laboratory workers was 1.69 (0.62-3.68) and among male laboratory scientists, after more than 10 years of work (4 cases), it was 3.11 (0.85-7.56). There was an elevated SIR for malignant melanoma among female scientists in laboratories (3.51, 0.96-8.98) and for male scientists in nonlaboratory departments (2.86, 1.05-6.22). The SIR for breast cancer among female laboratory scientists was 1.62 (0.78-2.98). CONCLUSIONS The present findings lend some support to an excess of brain tumors among male scientists and of breast cancer in female scientists in biomedical research laboratories.

Lung cancer risks in relation to vegetable and fruit consumption and smoking.

In a case‐control study on lung cancer, risk was analysed in relation to smoking habits and frequency of vegetable and fruit consumption. Lung cancer cases in West Sweden and population controls were interviewed using a questionnaire where the frequency of consumption of dietary items and smoking habits were assessed. The material presented comprises 177 female and 359 male confirmed cases of lung cancer and 916 population controls. There was a dose‐response relationship in regard to the number of cigarettes smoked and the number of years smoked, the latter factor being more important. After adjustment for number of cigarettes smoked/day and number of years smoked, the risk for those who seldom consumed vegetables was about twice of that among those who consumed vegetables frequently, both among nonsmokers, smokers and former smokers. This risk increase in relation to vegetable consumption also was present for different smoking categories. A similar tendency, although less pronounced, was found for fruit consumption. The results demonstrate that dietary factors are related to the risk for lung cancer, although smoking is the dominant risk factor.

Environmental chromium dust and lung cancer mortality

Abstract A register study was performed in a Swedish county to investigate lung cancer mortality in a population exposed to air pollutants from ferro-alloy industries. During 1961–1975, 810 lung cancer deaths were analyzed. A strong relation between population density and lung cancer mortality was found. When this factor was controlled no differences in mortality rates were found between the communities with ferro-alloy industry and the remainder of the county. A general increase in lung cancer mortality most marked for males was found over this time period.

Diet as Risk for Lung Cancer: A Swedish Case-Control Study

Abstract: A case-control study was undertaken to study lung cancer in relation to dietary habits, occupational exposure, and living in urban or country areas. Suspect lung cancer cases in West Sweden and population controls were interviewed using a food frequency questionnaire. The study comprised 177 female and 359 male cases and 916 controls. The cases mainly comprised former and current smokers (82% female, 95% male). For the analysis, cases were divided into the histological diagnoses adenocarcinoma and squamous cell, small cell, and adenosquamous cell carcinomas, as well as into smoking categories. A high frequency of consumption of vegetables was significantly related to a lower risk for adenocarcinoma and squamous cell and adenosquamous cell carcinoma among men and adenocarcinoma among women. A low odds ratio in the highest quartile of vegetable consumption in men was seen in all smoking categories. There were no significant protective effects from fruit in the different lung cancer subgroups, although a significant trend was found for heavy-smoking females. A high consumption of milk was related to an increased risk for lung cancer, especially adenosquamous cell carcinoma. The results suggest that the protective effect or risk due to dietary factors may affect different forms of lung cancer. The results from this as well as previous studies suggest a complex interaction between diet and lung cancer risk, involving the types of lung cancer as well as consumption patterns in the population.

Lung cancer, smoking and diet among Swedish men

In a prospective case-control lung cancer study in the west of Sweden, the relationship between lung cancer, smoking and dietary factors was investigated. Suspected cases were collected from pulmonary units at two central hospitals in the area investigated and population controls of the same age and sex were selected from registers. The majority of cases and controls were interviewed by specially trained nurses, using a food frequency questionnaire. The lung cancer diagnosis (ICD 7, 162.1) was made using data from the local cancer register. In an analysis based on 308 cases and 504 controls, a dose-related increase in lung cancer risk for smokers was found, although no significant risk was found for males smoking 1-10 cigarettes/day for less than 20 years. A lower consumption of vegetables was related to a higher risk, both for smokers and nonsmokers. A higher consumption of milk was related to an increased risk.

Pet birds and risk of lung cancer in Sweden: a case-control study.

Abstract Objective: To investigate the association between keeping birds and the risk of lung cancer in Sweden. Design: Case-control study based on cases of lung cancer and community controls. Interviews were performed by two nurses specially trained for this project. Setting: Three major referral hospitals located in southwest Sweden. Subjects: All patients aged 75 and under with newly diagnosed lung cancer and of Scandinavian birth who lived in one of 26 municipalities in Gothenburg and Bohus county or Alvsborg county. Potential control subjects matched on county of residence, sex, and closest date of birth were selected from population registries. In the context of a larger case-control study, information on pet birds was obtained from 380 patients with lung cancer (252 men) and 696 controls (433 men). Main outcome measures: Odds ratios for lung cancer in relation to whether or not pet birds were kept and the duration of keeping pet birds. Results: The adjusted odds ratio for ever versus never exposed to pet birds at home was 0.94 (95% confidence interval 0.64 to 1.39) for men and 1.10 (0.64 to 1.90) for women. There was no evidence of a trend for increased risk of lung cancer with duration of bird ownership. Conclusion: Bird keeping does not seem to confer any excess risk of lung cancer to Swedish men or women. Key messages A population based case-control study of lung cancer in southwest Sweden was conducted with questions about duration of pet bird ownership and types of birds owned No evidence of a trend for increased risk of lung cancer was observed with duration of ownership of birds Bird keeping does not seem to confer any excess risk of lung cancer in Sweden

Association between Precipitation Upstream of a Drinking Water Utility and Nurse Advice Calls Relating to Acute Gastrointestinal Illnesses

Background The River Göta Älv is a source of fresh-water for the City of Gothenburg (Sweden). We recently identified a clear association between upstream precipitation and indicator bacteria concentrations in the river water outside the intake to the drinking water utility. This study aimed to determine if variation in the incidence of acute gastrointestinal illnesses is associated with upstream precipitation. Methods We acquired data, covering 1494 days, on the daily number of telephone calls to the nurse advice line from citizens in Gothenburg living in areas with Göta Älv as a fresh-water supply. We separated calls relating to gastrointestinal illnesses from other medical concerns, and analyzed their association with precipitation using a distributed lag non-linear Poisson regression model, adjusting for seasonal patterns and covariates. We used a 0–21-day lag period for precipitation to account for drinking water delivery times and incubation periods of waterborne pathogens. Results The study period contained 25,659 nurse advice calls relating to gastrointestinal illnesses. Heavy rainfall was associated with increased calls the same day and around 5–6 days later. Consecutive days of wet weather were also found to be associated with an increase in the daily number of gastrointestinal concerns. No associations were identified between precipitation and nurse advice calls relating to other medical concerns. Conclusion An increase in nurse advice calls relating to gastrointestinal illnesses around 5–6 days after heavy rainfall is consistent with a hypothesis that the cause could be related to drinking water due to insufficient barriers in the drinking water production, suggesting the need for improved drinking water treatment.