Selected Cancer Mortality and Farm Practices in Iowa

Abstract

Death certificate analyses of white male Iowans over age 30 who died of multiple myeloma, non-Hodgkin's lymphoma, prostate cancer or stomach cancer between 1964 and 1978 were completed. Each case was matched to two controls on age (within two years) at death, county of residence, and year of death. Consideration of usual occupation, as recorded on the death certificate, resulted in the following odds ratios for mortality due to the specified cancers among farmers: multiple myeloma, 1.48; non-Hodgkin's lymphoma, 1.26; prostate cancer, 1.19; and stomach cancer, 1.32. Each is statistically significant (p less than 0.05). Odds ratios were computed separately for three birth cohorts according to counties stratified by crop and livestock production. Multiple myeloma was elevated in those born after 1890 and was associated with number of egg-laying chickens, hog production, insecticide use, and herbicide use. Non-Hodgkin's lymphoma was elevated in those born before 1901 and was associated with egg-laying chickens, milk products sold, hog production, and herbicide use. Although prostate cancer was elevated in those born before 1901, it was not associated with any agricultural practice. Stomach cancer was elevated in each birth cohort. It was associated with milk products sold, cattle production, and corn per acre.

Work environment and prostate cancer risk

“…Rotkin [37] indeed observed a significant relation to fertilizer use, but no clear association was found in the present study, nor in some other studies [30,[32][33][34]. Associations have been observed with cattle and sheep [34,38], with poultry [31,34,39], or with livestock production in general [40], No association, however, was detected in our study or in some others [30,33]. Brownson et al [40] reported an excess risk in agricultural crop production, but no association was found in our study, nor in others [30,34].…”

“…An increased OR was found for the numbers of days/year cases and referents used pesticides, but not for the proportions of cases and referent who applied these compounds. An association with pesticide ex posure was revealed in some previous studies among agricultural workers too [28,30,31]. However, in other studies among farmers [32,33] and among workers licensed to apply pesticides [34,35], no asso ciation was found.…”

Cancer among farmers. A review.

“…Mortality from non-Hodgkin's lymphoma in New Zealand showed a similar age pattern (72). In Iowa, however, the risk of non-Hodgkin's lymphoma was greater among farmers born before 1890 or dying after age 65 (17) and among farmers residing in counties where herbicide usage was high and in counties where chickens, hogs, and dairy products were major commodities. Results from case-referent studies in Sweden are consistent with the association between herbicide use and non-Hodgkin's lymphoma in Iowa and Wisconsin.…”

“…Multiple myeloma has been associated with farming in Washington and Oregon (64), Wisconsin (20), Iowa (17), and Texas (1). In Wisconsin, farmers born before 1906or dying after age 65 were at the highest risk (20), but no such pattern was discernable among Iowa farmers (17).…”

The non-Hodgkin lymphomas: A review of the epidemiologic literature

“…142 Other case-control studies that evaluated general classes of pesticides have reported odds ratios both above and below 1.0. 29,31,32,53,88,105,114,143 In a German case-control study that evaluated parental pesticide exposure and relative risk of NHL in children positive associations were observed with paternal and maternal exposure, based on small numbers. 144 Evaluating pesticides or categories of pesticides may obscure a chemical-specific association.…”