Environmental Epidemiology & Statistics Division

Research Highlights

 

In cooperation with the UMDNJ-New Jersey Medical School, the Division has continued to participate in the analysis of data from the $30 million Treatment of Lead-exposed Children (TLC) study. The principal results of this multicenter, randomized trial of succimer chelation therapy in young, lead-exposed children were published in the New England Journal of Medicine (New Engl J Med. 1421-1426. 2001). Unfortunately, chelation provided no benefit on cognitive and behavioral test results three years later when the children were 4-5 years old. Blood lead levels fell immediately in the chelated group and more slowly in the control group, but the levels in the two groups were indistinguishable within six months of the cessation of therapy. Two hundred and seven children have been enrolled in New Jersey, contributing to a total of 780 children from all the clinical centers combined. Dr. Rhoads serves as Chair of the National Steering Committee for the project. Further follow-up of these carefully studied children (to age seven years) is under way with funding from the National Institute of Environmental Health Sciences.

Dr. Rhoads is collaborating with Jim Zhang, Ph.D. and Paul Lioy, Ph.D. of the Exposure Measurement and Assessment Division, on a randomized field trial of various methods of cleaning up lead-contaminated dust in urban homes as well as different methods of assessing dust levels. The hypothesis being tested is to determine whether simpler methods of household cleaning will work as well as the combination of the special vacuum cleaners and more chemically active cleaning agents that are currently recommended. The study team completed enrollment of 127 houses in the year 2000. There was no systematic advantage of the special vacuum cleaners and cleaning agents on hard surfaces. Results for carpets are currently being analyzed. A related project, funded by the U.S. Environmental Protection Agency to determine whether simple methods will also work well for cleaning up contaminated dust generated by removal of lead-based paint is in the field.

Increases in mortality from prostate cancer over the past two decades have suggested that environmental influences may be contributing to this disease. For unknown reasons these increases have recently leveled off and decreased slightly. This could reflect a diminished exposure to an unidentified carcinogen or tumor promoter or it could be due to more effective control through screening. In order to test the latter hypothesis, Division members have mounted a large case-control study of prostate specific antigens (PSA) screening among prostate cancer decedents and healthy, age-matched male controls. The hypothesis is that if PSA screening is effective and accounts for the mortality reduction, it should be possible to show that men dying of this disease were less likely to have been screened than other men. The study is being funded by the National Cancer Institute. So far approximately, 400 cases and 250 controls have been recruited.

Joanna Burger, Ph.D. has been examining fish consumption and advisory information issued by governmental authorities at two sites: Newark-Bay Complex and in the Savannah River, in South Carolina. This has involved understanding attitudes and perceptions about fish consumption and advisories, and determining fish consumption rates and contaminants in the fish consumed. In both cases it is an equity issue in that in South Carolina African Americans consume far more fish than whites, and in Newark Bay, Hispanics and other minorities are consuming large quantities of fish. In addition, in Newark Bay, Dr. Burger has been interviewing anglers to determine the reasons they fish. The initiatve is aimed at generating potential intervention - in the quantities, parts of fish, and types of different species of fish consumed.

This past year, Daniel Wartenberg, Ph.D. has been examining risk assessment methodology and its impact on policy and risk management. Most recently, he has been studying limitations of Monte Carlo simulations in risk assessment and the implications it has on policy. His work in more traditional epidemiology includes field studies, reanalysis of data from studies conducted by other researchers, development of new methods and reviews of the literature. Recently, he completed an original analysis of data from the American Cancer Society looking at passive smoking and breast cancer mortality, and a cohort mortality study of workers at the Savannah River Site nuclear fuels production facility. Currently, he is initiating new work in the area of spatial epidemiology, and the geographic distribution of risk factors and disease. This includes emphasis on disease clusters, disease mapping, the use of spatial interpolation algorithms for exposure assessment, and innovative applications of geographic information systems (GIS) to epidemiology.

Joe Shih, Ph.D. has made considerable progress this year in augmenting the availability of statistical consultation in the Institute. He has recruited two new statisticians to the campus and has developed a biostatistical consulting service. In addition, he has personally consulted with a number of Institute investigators on the statistical analyses of their work.

Ronald Cody, Ph.D. has continued to provide statistical consultation to a number of Institute members during the year. In collaboration with Clifford Weisel, Ph.D., from the Exposure Measurement and Assessment Division he has been investigating the association of ozone and other irritants, along with environmental factors such as temperature, on the incidence of asthma. A new study is underway, using both visits to hospital emergency rooms and hospital admissions for asthma as outcome variables.