BTEX (Benzene, Toluene, Ethylbenzene and Xylene) concentrations found in Richmond County, New York, correlate with breast cancer mortality but not incidence

Staten Island, NY (Richmond County) breast cancer incident/mortality rates are significantly higher than the New York State rates from 1976-2004 according to NYS Department of Health/NYC Department of Health and Mental Hygiene (incidence 125.6±18.7 vs. 118.7±11.9; p=0.003; mortality 35.2±5.4 vs. 30.2±3.0; p<0.00002). One reason that the Staten Island Breast Cancer Research Initiative (SI-BCRI) was formed is to ask whether air pollution correlated with high breast cancer rates. To address this question, BTEX concentrations in ambient air were obtained as reported from the USEPA and correlated with Richmond County breast cancer incidence/mortality rates. Statistically significant correlations were found between Richmond County breast cancer mortality rates and total BTEX levels after a lag time of 1 year was applied to the data (r²=.325; p=0.03; 1990-2003), while no significant trends occurred for breast cancer incidence (r²=0.013; p=0.69; 1990-2003). Furthermore, Richmond County has been identified as having the highest relative risk of breast cancer mortality of the five boroughs of NYC from 1995-2005 (avg.=1.139, n=10; 95% CI 1.056-1.222). These data may reflect the fact that Richmond County's average annual ambient benzene concentrations from 1990-2004 is 11.82 µg/m3, which is almost 88 times the benchmark level believed to spur cancer in humans over a lifetime of exposure as established by National Air Toxics Assessment. We conclude that air pollution as measured by BTEX levels do not necessarily predict breast cancer incidence but instead may predict breast cancer mortality rates.