Do multiple environmental factors impact four cancers in women in the contiguous United States?

ABSTRACT

BACKGROUND: Though there has been an increasing concern about the effects that environmental exposures have on cancer, limited knowledge exists regarding multiple environmental factors on cancers in women. METHODS: We performed a spatial autoregressive model to examine the association between the Environmental Quality Index (EQI) and mortalities of four cancers in women (breast, cervical, ovarian and uterine cancer) based on county-level data, and explored these associations by urbanicity. The EQI, which included five domains (air, water, land, built environment and sociodemographic domain) estimated from 2000 to 2005 data, was obtained from the United States Environmental Protection Agency. The mortality rates for 3107 counties in the US in 2014 were obtained from the Institute for Health Metrics and Evaluation. RESULTS: We found that each unit increase in the overall EQI was positively associated with the increased mortality of breast, ovarian and uterine cancer (2.5%, 3.6% and 3.1% respectively), but was negatively associated with cervical cancer mortality. Among the environmental domains, the air and sociodemographic EQIs were positively associated with increased risks of breast, ovarian and uterine cancers. Additionally, built environment EQI was associated with breast and ovarian cancers; land EQI was associated with uterine and ovarian cancers. The sociodemographic EQI was negatively associated with cervical cancer mortality. Furthermore, we have developed a novel Environmental Quality Health Index (EQHI) in identifying environment-health risk of cancers in women at county level. CONCLUSIONS: Our findings suggest that breast, ovarian, and uterine cancer mortalities are positively associated with multiple environmental factors, while cervical cancer mortality is mainly negatively associated with sociodemographic factors. The novel EQHI might help identify spatially-based environment-cancer risk.