Nonlinearity in the Lung Cancer Dose–Response for Airborne Arsenic: Apparent Confounding by Year of Hire in Evaluating Lung Cancer Risks from Arsenic Exposure in Tacoma Smelter Workers

Arsenic-induced enhancement of ultraviolet radiation carcinogenesis in mouse skin: a dose-response study.

“…However, studies of skin or bladder cancer among persons consuming arseniccontaminated drinking water in Taiwan were consistent with linearity, although other forms could not be ruled out (Brown et al 1989(Brown et al , 1997Chiou et al 2001). Lung cancer in smelter workers was consistent with linear when analyzed according to the excess mortality approach but not when analyzed according to the standard mortality approach (Viren and Silvers 1999).…”

An updated inhalation unit risk factor for arsenic and inorganic arsenic compounds based on a combined analysis of epidemiology studies

“…Lubin et al (2000) investigated the absolute or additive risk model but found that it provided poorer fits to the data than the multiplicative relative risk model. Viren and Silvers (1999) fitted models to the Asarco cohort data using the same procedure as TCEQ with a slightly different model parameterization. After adjusting for the differences in model parameterizations, the TCEQ and Viren and Silvers (1999) parameters are identical.…”

“…Viren and Silvers (1999) fitted models to the Asarco cohort data using the same procedure as TCEQ with a slightly different model parameterization. After adjusting for the differences in model parameterizations, the TCEQ and Viren and Silvers (1999) parameters are identical. Viren and Silvers (1999), however, failed to adjust for the year of hire in their model fit to the total cohort.…”

“…The weights are the inverse of the squared SE's of the individual URFs. That is, Enterline and Marsh, 1982;Enterline et al, 1987aEnterline et al, ,b, 1995 Viren and Silvers (1999) found no association for those workers, (i.e., regression did not achieve statistical significance at P < 0.01 based on the corresponding likelihood ratio statistic).…”

“…URFs and arsenic 10 À5 -risk air concentrations were calculated using b values for all workers adjusting for year of hire, all workers with no adjustment for year of hire, and workers hired <1940 except for the Montana study. URFs were not calculated for the Tacoma smelter workers hired 1940+ because Viren and Silvers (1999) found no association for those workers, (i.e., regression did not achieve statistical significance at P < 0.01 based on the corresponding likelihood ratio statistic). The MLEs of URFs in Table 6 range from 9.03E-05 to 2.34E-04 per lg/m 3 while the 95% UCLs on the URFs range from 1.48E-04 to 6.03E-04 per lg/m 3 .…”