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Last Edited: 8/6/2010

Health Effects Study: Del Amo, Montrose
Written: 1987

In 1984 an epidemiological investigation was carried out in communities near the Del Amo and Montrose hazardous waste sites in Los Angeles by the Epidemiological Studies and Surveillance Section.  The Del Amo site contains wastes from the manufacture of synthetic rubber and ethylene beginning in the 1940s and ended in 1973.  The Montrose site housed a facility which produced the pesticide DDT from 1947 through the 1970s.  At the time of this study however, offsite chemical migration patterns and concentrations were not available for either site.  Thus, the study sought to evaluate various health outcomes using the communities’ proximity to the sites as an indirect measure of exposure.

Approximately 1000 adults in each of the Del Amo and Montrose communities participated in the study, which corresponded to 65 and 71 percent of the targeted individuals, respectively.  Information on about 500 children in each area was also obtained.  The results show that the participants from the Del Amo or the Montrose study areas have not reported elevated rates or unusual patterns of cancer, adverse reproductive outcomes, or mortality.  However, compared to the control area, the rates of several symptoms were elevated in the Del Amo and Montrose study areas, including skin irritation/rash and irritation of the eyes, upper respiratory tract, and throat.  
Two points should be kept in mind when interpreting the study’s results.  First, the findings pertain to the then-current residents of the study communities; the health status of people who moved away and long-term effects, if any, were not issues that this study was designed to address.  Second, the elevated symptom rates were not necessarily caused by either waste site.  The presence of other sources of chemical contamination in the area, the suggestion that some over-reporting of symptoms may have occurred, the potential bias from low response rates, and the absence of offsite chemical exposure measurements preclude definitively establishing either the Del Amo or Montrose sites as the source of the health problems reported.

Executive summary (Size:  42 KB)