Influence of years engaged in agriculture and number of pregnancies and deliveries on mortality of inhabitants of the Jinzu River basin area,Japan

Background: The occurrence of itai-itai disease is thought to be affected by such factors as pregnancy, lactation, hormonal disorders, aging, and calcium deficiency.

Aims: To study the influence of years engaged in agriculture and number of pregnancies and deliveries on the mortality of inhabitants of the Jinzu River basin area, which has been an endemic region for itai-itai disease.

Methods: From 6667 participants (3181 men, 3486 women; participation rate 93.4%) in the 1967 health survey, 3639 subjects (1591 men, 2048 women) whose years engaged in agriculture were established, and 2559 women/2410 women with a known number of pregnancies/deliveries were selected as the target population. These data were confirmed on the basis of self reported replies confirmed afterwards by interview. The survival survey was conducted for 6127 days from 1 August 1967 to 10 May 1984. Subjects were divided according to three water systems: the Jinzu River, non-Jinzu River, and mixed water system; the influence on mortality of the years engaged in agriculture and the number of pregnancies/deliveries was analysed using a Cox's proportional hazards model according to the water systems.

Results: The mean years engaged in agriculture and mean number of pregnancies/deliveries were not different among the three water systems. Cox's hazard ratios of these parameters to mortality were not statistically significant in the any of the water systems.

Conclusions: Neither the years engaged in agriculture nor the number of pregnancies/deliveries influenced mortality in subjects living not only in the non-Jinzu River basin but also in the Jinzu River basin using a Cox's proportional hazards model.

     

Total cadmium intake and mortality among residents in the Jinzu River Basin, Japan

This study investigated the relationship between total cadmium intake and mortality among rural inhabitants of the Jinzu River Basin, Japan. A follow-up survey was conducted for 6,128 days on 3,236 inhabitants. The rural communities were divided into 2 groups, one with a total cadmium intake of < 2.0 gm and the other > or = 2.0 gm. Standardized mortality ratios and a Cox's proportional hazard model indicated mortality risk was greater in the > or = 2.0 gm group, compared with the < 2.0 gm group. In the Jinzu River Basin, a total cadmium intake > or = 2.0 gm exerts an adverse influence on life prognosis.     

Cadmium exposure aggravates mortality more in women than in men

This study aimed to examine whether the mortality associated with exposure to cadmium (Cd) differs between the sexes. Target subjects were 14,604 (6,944 men, 7,660 women) from a list of all residents in the Jinzu River basin in 1967 and 1968. Trend of proportion of the population aged 70 years and older was significantly higher in women in the following decreasing order: non-Jinzu River basin, a region receiving a mixed water supply, and the Jinzu River basin. Sex ratios (proportions of population of men to that of women) in those aged 70 years and older became significantly higher in the same order. This tendency was compatible with the geographical distribution of the prevalence of abnormal urinary findings and Cd concentration in rice which was grown and consumed in the area. This study revealed that Cd exposure aggravates mortality more in women than in men.     

Mortality of inhabitants in an area polluted by cadmium: 15 year follow up.

OBJECTIVE--To assess the influence of environmental exposure to cadmium (Cd) on long term outcome of inhabitants living in an area polluted by Cd. METHODS--A follow up study for 15 years (from 1974-5 to 1991) was carried out on 2408 inhabitants (amounting to 95% of the target population, 1079 men and 1329 women) of the Kakehashi River basin in Ishikawa Prefecture, Japan. These inhabitants had been the subjects of the health impact survey in 1974-5 to evaluate (by measurement of urinary retinol binding protein (RBP)) renal dysfunction induced by Cd. Analysis of mortality was performed by dividing subjects into a urinary RBP positive (> or = 4 mg/l) group and RBP negative (< 4 mg/l) group. RESULTS--After adjustment for age with Cox's proportional hazard model, RBP > or = 4 mg/l showed a significant relation to mortality in both sexes. At this time, the mortality risk ratio of the RBP positive to negative group was 1.71 in the men and 1.42 in the women. When the SMRs according to causes of deaths in the RBP positive group were compared with those of the RBP negative group or the overall Japanese population increases of SMR for cardiovascular diseases, especially heart failure, and renal diseases were found in both sexes. CONCLUSION--These results suggest that the prognosis of the exposed inhabitants with renal tubular dysfunction is unfavourable, and these increases of mortality are due to heart failure and renal diseases.     

Urinary cadmium and mortality among inhabitants of a cadmium-polluted area in Japan

The influence of cadmium (Cd) body burden on mortality remains controversial. Excess mortality and the dose-response relationship between mortality and urinary cadmium excretion were investigated in this study among environmentally exposed subjects. A 15-year follow-up study was carried out on 3119 inhabitants (1403 men and 1716 women) of the Cd-polluted Kakehashi River basin, whose urinary Cd concentration was examined in a 1981-1982 health impact survey. The mortality risk of high urinary Cd (> or = 10 microg/g Cr) subjects after adjustment for age using Cox's proportional hazard model was higher than that of moderate urinary Cd (< 10 microg/g Cr) subjects in both sexes. When the subjects were divided into five groups according to the amount of urinary Cd (<3, 3-5, 5-10, 10-20, > or = 20 microg/g Cr), the mortality risk was significantly increased among the subjects with urinary Cd > or = 3 microg/g Cr in proportion to the increases in the amount of urinary Cd concentration after adjustment for age, especially in women. Furthermore, special causes of death among high and moderate urinary Cd were investigated, and mortality risk ratio for heart failure, which is a cause of death often diagnosed in cases with a gradual deterioration culminating in death, was significantly increased in both sexes, compared with the moderate urinary Cd subjects. Also, in women the mortality risk for renal diseases in the high urinary Cd subjects was significantly higher than that in the moderate urinary Cd subjects. These results suggest that a causal association between Cd body burden and mortality exists among inhabitants environmentally exposed to Cd but that no special disease may be induced except renal diseases.     

Investigation of renal damage among residents in the cadmium-polluted Jinzu River basin, based on health examinations in 1967 and 1968

The purpose of this study was to investigate the prevalence of renal disorders in the Jinzu River basin in Toyama Prefecture, Japan where Itai-itai disease was endemic, based on the results of epidemiological studies performed in 1967 and 1968. Furthermore, was there a regional accumulation of the prevalence of abnormal urinary findings in that area? Early morning urine samples were collected from 13 183 subjects (6155 men, 7028 women) who then responded to questionnaires about lifestyle and health. The subject participation rate was 90%. Our findings showed that subjects living in the area of the Jinzu River basin have significantly higher prevalence of abnormal urinary findings compared to subjects living in neighboring river basins and these geographical distributions demonstrated a definite regional accumulation in those areas. The findings of this study verified the regional accumulation of renal disorders in the Jinzu River basin and indicate an association of the occurrence of renal disorders with the water from the Jinzu River.     

Renal effects of environmental exposure to cadmium in middle-aged population of Jinzu River basin in Toyama, Japan: 2000-2002 study

OBJECTIVE: In 2000-2002, the effects of environmental cadmium (Cd) exposure on renal tubular function were investigated in men and women born between January 1, 1946 and December 31, 1955, and living in the Cd-polluted Jinzu River basin in Toyama. It is assumed that these generations had been exposed to Cd mainly through the consumption of rice and vegetables grown locally, in contrast to older generations who had been exposed not only through the consumption of rice but also by drinking river water polluted with Cd discharged from a mine. METHODS: Morning urine specimens, self-administered questionnaires and polished rice samples consumed daily were collected from 110 men and 121 women living in the polluted area and from 48 men and 45 women living in the reference area. RESULTS: Urinary Cd excretion level, an indicator of Cd accumulation in the kidneys, significantly increased with increased duration (years) of residence in the Cd-polluted area in both men and women. There was no case of urinary beta2-microglobulin (beta2-MG) level exceeding 1,000 microg/g Cr in either sex, in contrast to the high prevalence of beta2-MGuria observed in older generations. However, urinary beta2-MG and alpha1-MG levels were slightly but significantly increased with increased duration (years) of residence in the Cd-polluted area in women. CONCLUSIONS: The results indicate that men and women born between 1946 and 1955 and living in the Cd-polluted Jinzu River basin had Cd accumulation in the kidneys and a slight increase in urinary low-molecular weight protein level due to this accumulation.     

Evaluation of qualitative and quantitative tests for proteinuria and glucosuria as screening tests for cadmium-induced renal tubular dysfunction

To evaluate the screening tests for cadmium-induced renal tubular dysfunction, qualitative and quantitative tests for urinary protein and glucose have been done in 146 urine samples obtained from subjects who had lived in the cadmium-polluted Jinzu River basin in Toyama Prefecture, Japan. The subjects consisted of 66 men and 80 women aged 55 to 71 years with beta 2-microglobulinuria exceeding 1,000 micrograms/g creatinine. The results obtained from this study were as follows; 1) The positive reaction (above 1+) for protein by the dipstick method was seen in 19.7% of men and 20.0% of women, and for glucose using Tes-tape in 48.5% of men and 33.8% of women. 2) The geometric means of protein and glucose concentrations in urine were 16.4 mg/dl and 12.7 mg/dl in men, and 14.2 mg/dl and 6.8 mg/dl in women, respectively. 3) The criteria of the primary screening in the health survey system for the residents in cadmium-contaminated areas conducted by the Japan Environment Agency were a proteinuria level exceeding 10 mg/dl and a glucosuria above (+/-) with Tes-tape. Nearly all subjects with urinary beta 2-microglobulin exceeding 30 mg/g creatinine were screened by these criteria in both sexes, whereas only 52.9% of men and 30.0% of women who had urinary beta 2-microglobulin between 10 to 30 mg/g creatinine could be screened in this manner. These results indicate that semiquantitative tests are insufficient as initial tests for screening cadmium-induced renal tubular dysfunction.     

A comparison between health effects of cadmium and cadmium concentration in urine among inhabitants of the Itai-itai disease endemic district.

The relationship between urinary cadmium concentration (micrograms/g creatinine) and the health effects of cadmium exposure was studied in 406 inhabitants who lived in and around the Jinzu River basin. Cadmium concentration in urine was employed as the index of cadmium exposure. Total protein, glucose, calcium, and phosphorus in urine and calcium, inorganic phosphorus, and alkaline phosphatase in serum served as indices of health effects. On a group basis a close relationship was found between cadmium concentration in urine and health effects. Prevalence rates of indices of health effects increased proportionally with increasing cadmium concentrations in urine. It was concluded that cadmium concentration in urine expressed as micrograms/g creatinine is a useful parameter in estimating the health effects of cadmium exposure from the environment.     

Renal tubular dysfunction in male inhabitants of a cadmium-polluted area in Toyama, Japan--an eleven-year follow-up study

An eleven-year follow-up study was carried out to elucidate the changes in the level of environmental exposure to cadmium (Cd) from rice after soil replacement of polluted paddy fields and these effects on urinary excretion of Cd in male inhabitants of a Cd-polluted area in Toyama, Japan. In addition, the prevalence of renal tubular dysfunction (RTD) was examined to clarify the progress of Cd-induced RTD. One hundred and twenty-seven male inhabitants born between 1914 and 1929 in 11 districts of the Cd-polluted Jinzu River basin and 31 reference subjects in 2 adjacent districts were examined twice in 1985-86 and 1996-97. The geometric means of Cd concentrations in polished rice (Cd-R) in the Cd-polluted areas were 0.18 ppm in 1985 and 0.21 ppm in 1986; these values were significantly higher than those of the reference areas (0.13 ppm in 1985 and 0.12 ppm in 1986). After 11 years, the Cd-R levels were significantly decreased to approximately half (0.08 ppm in 1996, 0.12 ppm in 1997) due to soil replacement of polluted paddy fields, which has been carried out since 1980. The mean Cd levels in urine (Cd-U) were significantly reduced from 7.9 and 9.5 microg/g creatinine in the initial study to 6.9 and 6.8 microg/g creatinine in the follow-up study. However, the prevalence of RTD, which was determined by urinary beta2-microglobulin exceeding 1 mg/g creatinine and urinary glucose exceeding 150 mg/g creatinine, increased from 18 and 23% in the 1985-86 study to 25 and 32% in the 1996-97 study, and a total of 12 new cases (12%) of RTD were found. Whereas, only one subject (4%) in the reference control areas was identified as RTD. Cd-induced RTD was prevalent, progressive and irreversible for male inhabitants of the Cd-polluted Jinzu River basin, although the environmental exposure to Cd through rice was significantly reduced by soil replacement of polluted paddy fields.     

Mortality among individuals diagnosed with glucose intolerance by the 75 g oral glucose tolerance test in rural Japanese communities

OBJECTIVE: To examine mortality among individuals confirmed to have glucose intolerance by the 75 g oral glucose tolerance test (OGTT) in rural communities. METHODS: Subjects were 1,639 residents of seven rural communities in Japan (total population size = 54,000) who underwent an OGTT as a secondary screening test for diabetes during 1987-95 and had received no medication for diabetes at baseline. OGTT results were classified as diabetes (n = 471), impaired glucose tolerance (IGT) (n = 408), or normal glucose tolerance (NGT) (n = 760), according to the recommendations of the American Diabetes Association. Indirect age-adjusted mortality rates and standardized mortality ratios (SMRs) for diabetes and IGT groups were calculated using age-stratified mortality rates for people aged 40-89 in the communities as the standard population. Relative risks of death and 95% confidence intervals (CI) for diabetes and IGT were calculated using Cox's proportional models, adjusted for age and baseline factors such as body mass index (BMI), total cholesterol, hypertension, smoking, alcohol drinking, history of diabetes, and family history of diabetes. RESULTS: During 9.4 years of follow-up, we recorded 70 deaths for the NGT, 46 for the IGT, and 71 for the diabetes group. The SMRs for IGT and diabetic men and women were not significantly increased in comparison with the standard population values. However, when analyzed in our cohort, age-adjusted relative risks of death for IGT and diabetes versus NGT men were 1.10 (9.5% CI: 0.72-1.67) and 1.54 (95% CI: 1.05-2.24), respectively, whereas, the risks among women did not significantly vary. Finally, multivariate analysis, further adjusted for the baseline factors, indicated the relative risk of mortality with diabetes in men to be significantly increased (relative risk = 1.74, 95% CI: 1.11-2.75). CONCLUSION: During follow-up, mortality rates among screened IGT and diabetes were not significantly higher than those in general. Nonetheless, we found that diabetes elevated the risk of death in our cohort, primarily in men.     

Causes of death and renal tubular dysfunction in residents exposed to cadmium in the environment

Objectives

To clarify the causes of death of residents with renal tubular dysfunction induced by cadmium (Cd) in the environment.

Methods

A 15 year follow up study was performed with the inhabitants living in the Cd polluted Kakehashi River basin in Japan. Standardised mortality ratios (SMRs) for causes of death, classified by ICD‐9, were computed using the person‐years method to investigate the excess mortality of subjects with urinary β2‐MG (microglobulin) ⩾1000 μg/gCr. Mortality risk analysis was performed using Cox''s proportional model to compare mortality between subjects with urinary β2‐MG ⩾1000 and <1000 μg/gCr, and to investigate the relationship between the degree of urinary β2‐MG and mortality.

Results

Excess mortality due to heart failure and cerebral infarction in both sexes, and nephritis and nephrosis in men, was observed among subjects with urinary β2‐MG ⩾1000 μg/gCr. Significant increases in mortality risk for cerebral infarction in men and for malignant neoplasms in women with urinary β2‐MG ⩾1000 μg/gCr were observed during the first five year observation period. For nephritis and nephrosis, the mortality risks for men and women with urinary β2‐MG ⩾1000 μg/gCr significantly increased over the 15 year observation period. The mortality risks for heart failure and cerebral infarction increased in proportion to the increased urinary β2‐MG in both sexes. Increased mortality risks for nephritis and nephrosis were identified in the subjects with urinary β2‐MG ⩾10000 μg/gCr in both sexes.

Conclusion

Renal tubular dysfunction induced by Cd affected the causes of death, and mortality for heart failure, cerebral infarction, and nephritis and nephrosis was increased among inhabitants living in a Cd polluted area in Japan. In women, cancer mortality may have been increased while Cd pollution was ongoing.     

Prediction of mortality from findings of annual health checkups utility for health care programs

OBJECT: To clarify relationships between the findings of annual health checkups and mortality in men and women living in Ibaraki prefecture. METHOD: The subjects were 32,705 men and 63,959 women aged 40 to 79 years who participated in annual health checkups in 1993. They were followed up until November 30, 1998, with a systemic review of resident registration and death certificates. The Cox's proportional hazards model was used to estimate relative risk, after adjustment for age, smoking status, usual alcohol intake, hypertension category, serum total cholesterol, HDL cholesterol, blood glucose, serum creatinine, body mass index (BMI) and urinary protein. RESULTS: During the 5.2-year follow-up, there were 2,937 deaths (including 384 deaths from stroke, 242 from coronary heart disease and 1,305 from cancer). Significant predictors of mortality from all causes were smoking, usual alcohol intake, hypertension, low serum total cholesterol, low BMI, high blood glucose level, proteinuria for men and women, and low HDL cholesterol for men, and high serum creatinine for women. Significant predictors of mortality from all cardiovascular diseases were smoking, hypertension, low BMI, high serum creatinine, proteinuria for men and women, usual alcohol intake and low HDL cholesterol for men, and serum total cholesterol and high blood glucose level for women. Significant predictors of mortality from stroke were hypertension, low BMI, high serum creatinine for men and women, and proteinuria for women. Significant predictors of mortality from coronary heart disease were smoking, high serum total cholesterol, high blood glucose level, proteinuria for men and women, hypertension, low HDL cholesterol for men. Significant predictors of mortality from cancer were smoking, usual alcohol intake, BMI for men and women, low serum total cholesterol, low HDL cholesterol and proteinuria for men, and high blood glucose level for women. Smoking, usual alcohol intake, low HDL cholesterol and proteinuria were significant predictors of mortality from lung cancer for men. CONCLUSION: Smoking, usual alcohol intake, hypertension, BMI, serum level of total cholesterol, HDL cholesterol, blood glucose, creatinine, and urinary protein are significantly associated with mortality. We obtained the new finding that serum creatinine level is a significant predictor of mortality from all cardiovascular diseases in Japanese men and women, and that the multivariate relative risk in female moderate alcohol drinkers (46-68 g ethanol intake/day) vs non-drinkers is significantly elevated for death from all causes. The results of our study are useful for planning of health care education and services.     

Relationship among prevalence of patients with Itai-itai disease, prevalence of abnormal urinary findings, and cadmium concentrations in rice of individual hamlets in the Jinzu River basin, Toyama prefecture of Japan

This study investigated the associations among prevalence of patients with Itai-itai disease, and prevalence of abnormal urinary findings and cadmium (Cd) concentrations in rice in individual hamlets of the Jinzu River basin. From the 13,183 participants of the 1967 and 1968 health examinations, we selected 3,094 subjects as the target population who had resided in the current hamlet for a total of 30 years or longer and aged >/=50 years, and in the hamlet both the Cd concentration in rice and prevalence of patients with Itai-itai disease were known. When the inhabitants were divided into four groups according to the Cd concentration in rice or prevalence of abnormal urinary findings, significant relationships among three factors (Cd concentration in rice, prevalence of abnormal urinary findings and prevalence of patients with Itai-itai disease) were demonstrated clearly using the Cochran-Armitage test. Correlation coefficients among the three factors in 55 hamlets showed that the prevalence of the patients with Itai-itai disease increased according to increases in the mean Cd concentration in rice and increasing prevalence of urinary findings. This study demonstrated that Itai-itai disease is induced by exposure to environmental Cd and that renal dysfunction plays an important role in its development.     

Increased urinary β2-microglobulin and mortality rate by cause of death in a Cadmium-polluted area

To clarify the effect of environmental cadmium (Cd) exposure on the life prognosis of inhabitants living in a Cd-polluted area, the standardized mortality ratio (SMR) according to cause of death in urinary β 2-microglobulin (β2-MG)-positive subjects (≥1000 μg/gCr) was compared to that of the Japanese general population and β2-MG-negative subjects (β 1000 μg/gCr). The SMR for all causes of death of both sexes was higher than that of the Japanese general population and β 2-MG-negative subjects. Among women, the SMR for malignant neoplasms was higher than that of β 2-MG-negative subjects. For cardiovascular disease and cerebrovascular disease, especially heart failure and cerebral infarction, SMRs were significantly higher in both sexes. The SMR for renal diseases was significantly high in the men and tended to be high in the women.     

Ethnic differences in cause specific mortality among hospitalised patients with diabetes: a linkage study in New Zealand

STUDY OBJECTIVE: To describe patterns of excess mortality among patients with diabetes in three ethnic groups. DESIGN: A linkage study of national hospital discharge records to death records. SETTING: New Zealand. PARTICIPANTS: The study included 74 847 patients (11,268 Māori, 5730 Pacific, and 57,849 non-Māori/non-Pacific) aged over 25 years with a hospital discharge diagnosis of diabetes between 1988 and 2001. By the end of 2001, 29,295 (39%) of the cohort had died. Based on the underlying cause of death, standardised mortality ratios (SMRs) (95% confidence intervals) were calculated for each ethnic group and sex. MAIN RESULTS: Comparing the mortality patterns of patients with diabetes to the general population of the same ethnic group, adjusting for age and calendar period, all cause SMRs were higher for Māori women and men: 3.80 (95% CI: 3.64 to 3.97) and 3.44 (95%CI: 3.30 to 3.58) than for Pacific (men: 2.41 (95%CI: 2.21 to 2.61); women: 2.23 (95%CI: 2.06 to 2.41)) and non-Māori/non-Pacific (men: 2.98 (95%CI: 2.93 to 3.04); women: 2.99 (95%CI: 2.93 to 3.04)) people. SMRs were significantly raised for several causes of death, including cardiovascular disease and many site specific cancers. CONCLUSIONS: The pattern of excess mortality among Māori with diabetes may relate to severity of disease. This needs further investigation, as the excess mortality may be amenable to intervention.     

Mortality among a cohort of banana plantation workers in Costa Rica

The nematocide 1,2-dibromo-3-chloropropane (DBCP), widely used in Costa Rica during the late 1960s and 1970s, causes sterility in men and is a possible carcinogen. Mortality among a cohort of Costa Rican banana plantation workers was investigated. The cohort included 40,959 individuals who worked on banana plantations between 1972 and 1979. Employment records were linked with the Costa Rican Mortality Registry to determine outcomes through 1999. Standardized mortality ratios (SMRs) were calculated for all causes of death. Poisson regression was also used to calculate mortality risk estimates by duration of employment, but provided no additional insight. All-causes SMRs were 0.77 for men (95% CI 0.75-0.80) and 0.90 for women (95% CI 0.80-1.02) relative to national mortality rates. Mortality from septicemia was significantly higher than expected. Nonsignificant increases in mortality were also observed for testicular cancer, penile cancer, Hodgkin's disease, and Parkinson's disease in men, and for cervical cancer and lung cancer in women.     

Estimation of Benchmark Rice Cadmium Doses as Threshold Values for Abnormal Urinary Findings with Adjustment for Consumption of Jinzu River Water

We performed this study to determine whether both eating cadmium (Cd)-polluted rice and drinking and/or cooking with Jinzu River water are associated with renal tubular dysfunction. A multiple logistic regression analysis of retrospective data indicated that both factors may contribute to this condition. Estimated threshold values of rice Cd concentration in men were 0.13–0.27 ppm and 0.09–0.18 ppm in women, without adjustment for use of Jinzu River water. The additional influence of drinking and/or cooking with Jinzu River water was estimated to be about 0.008 ppm.     

Are women more sensitive to smoking than men? Findings from the Renfrew and Paisley study

BACKGROUND: Prescott et al. found that the relative risks associated with smoking for respiratory and vascular deaths were higher for women who inhale than for inhaling men, and found no gender differences in relative risks of smoking-related cancers. The purpose of the present study was to assess whether these findings are reproducible, using data from the Renfrew and Paisley study. METHODS: Age-standardized mortality rate differences and age-adjusted mortality rate ratios (using Cox's proportional hazard model) were calculated for male and female smokers by amount smoked compared with never smokers. These analyses were repeated after excluding non-inhalers. RESULTS: The all-cause mortality rate ratio was higher for men than for women in all categories of amount smoked, although this difference was only statistically significant in the light smokers (1.83 [95% CI : 1.61-2.07] for men and 1.41 [95% CI : 1.28-1.56] for women, P = 0.001). The cause-specific mortality rate ratios tended to be higher for men than for women, and this difference was most substantial for neoplasms (2.57 [95% CI : 2.01-3.29] for male light smokers and 1.35 [95% CI : 1.14-1.61] for female light smokers, P < 0.001) and, in particular, for lung cancer (11.10 [95% CI : 5.89-20.92] for male light smokers and 4.73 [95% CI : 2.99-7.50] for female light smokers, P = 0.03). Furthermore, looking at the rate differences the effects of smoking were uniformly greater in men than in women. These results were virtually unchanged after excluding non-inhalers. CONCLUSION: We found similar results to Prescott et al. when all smokers were considered, but could not reproduce their findings when non-inhalers were excluded. Given the fact that we showed greater rate differences in men than in women, we think that it is too early to conclude that women may be more sensitive than men to some of the deleterious effects of smoking.     

Mortality rates in rural and urban areas of Brittany

Relative differences in environment, behaviour, social composition as well as access to health care tend to suggest that levels of health may vary between urban and rural areas. The aim of this study was to identify rural-urban variations in mortality risks in the region of Brittany for the period from 1988 to 1992. The definition of urban and rural areas used adhered to that of the zoning of urban areas established by the INSEE (the National Statistical Office). The amalgamation of all causes of standardised mortality ratios (SMR) show only a moderately increased risk in the rural areas compared with the overall regional level (+4% in men, +5-7% in women). The analysis of cause specific SMRs display higher rural mortality for cardiovascular diseases and external causes of death, road traffic accidents in particular (+24% in men). Among all specific causes investigated, only lung cancer mortality risk appears to be higher in urban areas.