Association Between Kidney Cancer and Occupational Exposure to Trichloroethylene.

OBJECTIVE: This study investigates the association between occupational exposure to trichloroethylene (TCE) and kidney cancer, as this correlation has been questioned. METHODS: The incidence of cancers was studied in a dynamic cohort of 997 male workers who for many years had been occupationally exposed to TCE. RESULTS: During a 50-year observation period, 13 cases of kidney cancer were observed (7.5 expected) with a standardized incidence ratio of 1.7 and a 95% confidence interval of 1.0 to 3.0. Four other cases, not included in the SIR analysis, were also observed. Long-term TCE exposure was positively confirmed for 14 of the 17 incident cases. There is reason to assume that the remaining cases also had been exposed to TCE. CONCLUSIONS: The present study supports the view that TCE is a kidney carcinogen.

More forearm fractures among urban than rural women: the NOREPOS study based on the Tromsø study and the HUNT study.

Higher rates of hip fracture and all fractures combined have been observed in urban compared with rural areas, but whether there are urban-rural differences in distal forearm fracture rates is less studied. The aim of this longitudinal study was to compare the incidence of forearm fracture in postmenopausal women in urban and rural areas in Norway and to investigate risk factors that could explain potential fracture differences. The study included data from 11,209 women aged 65 years or more who participated in two large health studies, the Tromsø Health Study in 1994-1995 and the Nord-Trøndelag Health Study in 1995-1997. Forearm bone mineral density (BMD) was measured by single-energy X-ray absorptiometry in a subsample of women (n = 7333) at baseline. All women were followed with respect to hospital-verified forearm fractures (median follow-up 6.3 years). A total of 9249 and 1960 women lived in areas classified as rural and urban, respectively. Urban women had an increased forearm fracture risk [relative risk (RR) = 1.29, 95% confidence interval (CI) 1.09-1.52] compared with women in rural areas. Rural women had higher body mass index (BMI) than urban women, and the RR was moderately reduced to 1.21 (95% CI 1.02-1.43) after BMI adjustments. Rural women had the highest BMD. In the subgroup with measured BMD, adjustments for BMD changed the urban versus rural RR from 1.21 (95% CI 0.96-1.52) to 1.05 (95% CI 0.83-1.32), suggesting that BMD is an important explanatory factor. In conclusion, higher rates of forearm fractures was found in urban compared with rural women.

Incidence and seasonal variation in hip fracture incidence among elderly women in Norway. The HUNT Study.

There is a substantial variation in hip fracture incidence between populations. The Scandinavian countries have the highest incidence of hip fractures worldwide, and latitude and seasonal variation have been discussed as possible reasons for the high fracture incidences. The purpose of this study was to investigate time dependent and seasonal variation of hip fractures in a population based cohort of women aged 65+ residing in a rural county in Norway and followed for 9.3 years. Information at baseline was collected as part of The Nord-Trøndelag Health Study (HUNT) during 1995-97, and 8362 women with no previous hip fracture and with a mean age of 74.3 years were included in the study. All hip fractures occurring after inclusion in the health study were registered (mean follow-up: 9.3 years) by medical journals and x-ray reports. A total of 5661 of the women had their forearm bone mineral density (BMD) measured by single energy x-ray bone densitometers (SXA) as part of HUNT. In total, 782 women sustained a first hip fracture during follow-up, and the overall hip fracture incidence rate per 1000 person-years was 13.1 (95 % CI: 12.2-14.1). The hip fracture incidence increased exponentially by age from 2.1 (95% CI: 1.2-3.8) in the age group 65-69 years to 49.7 (95% CI: 41.2-59.8) among the women aged 90+, respectively. In age-stratified analyses no changes in the incidence of hip fractures were observed during the nine years of follow up. The occurrence of fractures varied by season of the year, characterized by higher fracture rates during the winter months. In conclusion, the hip fracture rates in this population of elderly women are highest in the winter months. There was, however, no indication of an increasing hip fracture incidence in this rural area. Compared to similar studies from more urban areas in Norway, the hip fracture rates in this population seem somewhat lower.