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Public Health Assessment
Ciba-Geigy Corporation
(Dover Township) Toms River, New Jersey
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Conclusions
Hazard Category for the Ciba Geigy Corporation Site
Based upon a weight-of-evidence analysis of the health and environmental information compiled, each Public Health Assessment assigns a hazard category (see Appendix) in response to the public health risk posed by the site being evaluated. Each category relates to a set of additional actions or interventions that may be considered by the ATSDR, the NJDHSS or other public health agencies, as well as recommendations for further action to the USEPA, the NJDEP, or other environmental agencies.
The Ciba-Geigy Corporation Toms River Plant site is considered by the ATSDR and the NJDHSS to have represented a public health hazard because of past exposures. This determination is based upon the following considerations, taken together:
1) the presence of a completed exposure pathway in the past through the community water supply to dyes and possibly other chemicals, to a potentially large population;
2) the presence of a completed exposure pathway through the use of private wells (for irrigation and possibly for potable use at some time hi the past) in the Cardinal Drive/Oak Ridge Parkway to VOCS;
3) toxicological evaluations;
4) epidemiologic studies from other communities and workplaces suggesting that exposure to dyes and VOCs may increase the risk of certain cancers and other adverse health outcomes; and
5) the presence of an excess of childhood cancers in the community.
Certain wells at the Holly Street well field of the community water supply were documented to be contaminated in 1965 and 1966 with dyes or dye -intermediates, nitrobenzene, and possibly other chemicals. The nature, magnitude and duration of exposure to these contaminants is not fully known, and the toxicological characteristics of some of the chemicals is not well understood. Since the Holly Street well field was a principal source of water for the community
water supply at that time, a large number of persons were likely exposed to contaminated water. Groundwater beneath the CGC site has been contaminated with high levels of VOCS, metals, and possible other chemicals. Contaminated groundwater has migrated off-site, and private irrigation wells in the Cardinal Drive/Oak Ridge Parkway area adjacent to the CGC site were found to be contaminated with VOCs and metals in the mid-1980s. Use of private irrigation wells
may result in exposure through dermal contact or inhalation of VOCs or dermal contact; if wells in the area had been used for potable purposes in earlier years, exposure potential could have been higher. Although uncertainties in exposure and toxicological information make the assessment of public health implications difficult, further epidemiologic evaluation is warranted in order to evaluate the public health significance of past exposures to contaminants from the site.
Current conditions indicate that although groundwater remains contaminated at levels of public health concern, completed human exposure pathways to contaminants from the CGC site have been interrupted. The exposure pathway associated with the community water supply wells of the Holly Street well field was reduced and/or interrupted through the construction of an outfall pipeline to re-direct wastewater from the Toms River to the Atlantic Ocean. The exposure pathway associated with private wells in the Cardinal
Drive/Oak Ridge Parkway areas has been interrupted through a well testing and sealing initiative by the CGC and the USEPA, and regulatory efforts by the Ocean County Health Department to monitor the location, and ensure the quality of, new wells in potentially affected areas. For these reasons the ATSDR and the NJDHSS have concluded that currently there arc no documented completed human exposure pathways associated with the CGC site, and thus, are categorizing the CGC site as representing no apparent public health
hazard under present conditions. Should the ATSDR or the NJDHSS become aware of additional information regarding CGC-related human exposure pathways, this determination may be reconsidered.
On-site source areas remain contaminated. Disposition of on-site contaminants is being considered by the USEPA through a Feasibility Study (for Operable Unit 2). Because there remains a potential for future exposure pathways to site-related contaminants if on-site areas remain unremediated, the ATSDR and the NJDHSS support remedial actions serving to interrupt exposure pathways.
Other potential exposure pathways in the past include inhalation of air contaminants from on-site manufacturing and waste disposal activities. With the closure of operations at the Toms River Plant, the air pathway is interrupted. In addition, site security measures have likely interrupted the potential for exposure of trespassers to on-site contaminated soils. There is no evidence that breaks in the outfall pipeline have resulted in human exposure to CGC-related contaminants through contaminated soils, sediments or groundwater, although other contaminants were evident in some of the private residential wells sampled.
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