Two Health-Related Studies

Two separate public health evaluations related to the WR Grace Superfund Site in Acton, MA have recently been conducted.

1. Public Health Risk Assessment (PHRA) by WR Grace, under the USEPA (US Environmental Protection Agency) guidance: This quantitative risk assessment was undertaken to help determine the future level of cleanup required at the site. It assumes exposure to contaminated groundwater on the site, at concentrations present when the PHRA was conducted. It does not assess public health risks related to previous contamination levels in the drinking water or elsewhere.

A July 1, 2005 Public Review Draft of the Public Health Risk Assessment was prepared for WR Grace by Menzie-Cura & Associates, Inc. and can be found in the public repository at the Acton Memorial Library. The risk assessment divided the site into six groundwater regions and found increased health risks in all six areas due to potential future exposures to groundwater contaminants. The assessed cancer risk in the six groundwater areas ranged from 2 in 1000 to 6 in 100 (PHRA Table ES-1).

See: Public Health Risk Assessment, EPA Superfund cleanup, for excerpts from the 2005 WR Grace Public Health Risk Assessment, conducted under EPA guidance.

EPA website: http://www.epa.gov/region01/superfund/sites/graceacton/

2. Public Health Study by ATSDR (Agency for Toxic Substances and Disease Registry): ATSDR (a federal agency under the Centers for Disease Control in Atlanta, Georgia) reported in 2003 that this separate study would consider past and/or present exposures to site contaminants and look at available public health data, including cancer rates. It would not evaluate the effect of exposure to multiple chemicals at once, but instead evaluate risk associated with each chemical in isolation. It also will not assess areas where it is assumes that there is no “completed exposure pathway”. The ATSDR study includes both qualitative and quantitative factors and “professional judgement”.

In August 2008, ATSDR released a public comment version of their Public Health Assessment. It generally found no apparent health hazard in most exposure scenarios, however it did note that the limited public well water data that was available from the late 1970’s had TCE levels that may have exceeded health guidelines. Also there was an increased lifetime risk from adult trespasser contact with contaminated sediments, and there was a higher than expected occurrence of central nervous system and brain cancer from 1982 to 2000, that was statistically significant during 1982-1987. (See Appendix G of the report for a discussion by the MA Department of Public Health on the central nervous system and brain cancer incidence.) See further information about the 2008 ATSDR study, including an index of topics at: ATSDR Public Health Assessment – Status Update . Also see: ACES Comments on ATSDR Health Study; Oct. 2008.

ATSDR website: http://www.atsdr.cdc.gov

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