Association between Renal Tubular Dysfunction and Mortality among Residents in a Cadmium-Polluted Area, Nagasaki, Japan.

Abstract

A retrospective cohort study was carried out to clarify the effect of exposure to environmental cadmium (Cd) on mortality. A total of 256 residents aged 50 years or older, living in Sasu, a Cd-polluted area in Tsushima Island in Nagasaki Prefecture, Japan, were followed from July 1979 to February 1989. The expected number of deaths calculated was based on the sex-and age-specific mortality rate in Tsushima Island in 1985. In Sasu residents of both sexes with urinary R2-microglobulin (M2-m) concentration greater than 1,000 pug/g creatinine in 1979, observed deaths were greater than expected. However, the p value of the difference was less than 0.05 only in men. The relationships of age, mean blood pressure, urinary /32-m and urinary Cd concentration to mortality were examined using Cox's proportional hazards model. Urinary R2-m was independently and significantly related to mortality in men but not in women. The results suggest an association between Cd-induced renal tubular dysfunction and mortality.

Association between Cadmium-Induced Renal Dysfunction and Mortality: Further Evidence.

“…In the previous report, we followed 256 residents in the Sasu area from July 1979 to February 1989, and observed a significant relationship between urinary /32-m excretion and mortality only in men (Iwata et al 1991), whereas in the present study, urinary /32-m levels were significantly related to mortality in both sexes. The reason for the previously observed absence of a significant relationship between urinary N2-m excretion and mortality in women is considered to be as follows : between July 1979 and May 1982, the mortality of women in the normal N2-m group (<1,000 ,u g/g cr) was relatively high, and the mortality in the increased /32-m group (>1,000 pg/g cr) was relatively low ; three of eight deaths (37.5%) in the normal /32-m group and six of 25 deaths (24.0%) in the increased R2-m group occurred between July 1979 and May 1982.…”

“…The sex-and 5-year-age-specific mortality rates for the entire population of Tsushima Island in 1985 (Nagasaki Prefecture 1985; Statistics Bureau, Management and Coordination Agency 1985) were used as the standard mortality. The propriety of this selection has been discussed earlier (Iwata et al 1991). …”

“…The Sasu area had been polluted by Cd discharged from a zinc mine. Changes in the Cd-pollution of this area and in the Cd exposure experienced by residents in this area have been described in detail elsewhere (Iwata et al 1991). We have performed health surveys in the Sasu area six times, in 1979, 1982, and from 1986 to 1989 Nakano et al 1985 ;Tohyama et al 1986 ;Iwata et al 1990).…”

“…In our preceding paper, we reported the results of a follow-up study on residents of Sasu, a Cd-polluted area on Tsushima Island, Nagasaki Prefecture, Japan (Iwata et al 1991). In this earlier study, 256 participants of a health survey carried out in 1979 were followed to 1989.…”

Follow up study of renal tubular dysfunction and mortality in residents of an area polluted with cadmium.

“…The soil of these districts had been contaminated by an exhaust containing cadmium from a copper refinery. The geometric mean of cadmium excretion in faeces from Kosaka residents was 146 pg/day in the mid 1970s, a value roughly [3][4][5][6] Urinary #,-microglobulin (/,-m) concentration was determined by radioimmunoassay with Phadebas /2-microtests (Pharmacia/Shionogi, Osaka), and urinary total amino nitrogen concentration by the trinitrobenzene sulphonic acid method.…”