No smoking gun in cancer cluster study

A study of a cluster of cancer cases near Millsboro appears to show the illnesses were not directly related to pollution coming from the Indian River power plant.

After a number of cancers were diagnosed near Millsboro, health officials labeled the area a cancer cluster. A research firm, RTI International was hired to conduct a $360,000 study to determine if the higher numbers of colorectal, lung and kidney cancers, melanoma and non-Hodgkins lymphoma were caused by fine particulate matter of mercury, nitrogen and phosphorus emissions from the coal-fired power plant.

The study, commissioned in 2011, focused on 32 Millsboro-area volunteers who took part in a series of blood, hair and urine tests. State health officials will discuss an update on the cancer cluster study May 21 during a meeting of the Delaware Cancer Consortium. A public meeting on the cancer cluster is set for May 28.

The study has attracted a number of critics who say the sample size was too small and the testing was too limited.

Overall, the study found the power plant contributed less air pollution than large nearby cities such as Washington, D.C., Baltimore and Philadelphia.

“There is not a real smoking gun,” said Emily Knearl, spokeswoman for the Division of Public Health. “Researchers found when there was poor air quality in large cities outside of Delaware, then about three days later it showed up here.”

Smoking was also blamed for poor indoor air quality, Knearl said.

Funded by the Division of Public Health and the Delaware Department of Natural Resources and Environmental Control, the study tested the urine samples for barium, beryllium, cadmium, lead, arsenic, selenium and others. The blood samples were tested for cadmium, mercury and lead. In addition to the samples, volunteers also completed a questionnaire and a daily log, Knearl said.

Millsboro volunteers were compared with a Seaford control group, and researchers found similarity in concentrations and elements in the tests. From this, researchers concluded that local source of pollution did not significantly impact particulate matter in the air.

According to the preliminary report issued by Division of Public Health, the volunteers in the study had fewer volatile organic compounds in their blood than expected. Researchers found the elements in blood and urine did not consistently increase when the power plant was running.

The report concludes past exposures likely contributed to current measures of elements in the blood or urine. It also said personal exposures through work or recreation could have contributed more to cancer risk than the power plant emissions.

“Since cancer results from years of exposures, these recent measurements after the installation of needed pollution controls don't tell us about past exposures in these areas,” said John Austin of Citizens for Clean Power. Austin said he hopes the final report, which will be released in a few weeks, notes differences in the chemical body burdens of the areas with higher and lower cancer rates, while all are in close proximity to the plant.

“Certainly, more studies are needed to understand these elevated rates,” Austin said. “However, the likelihood of finding a smoking-gun cause of elevated cancer rates is not very likely when there are potentially numerous contributing factors.”

“Further studies are under discussion,” Knearl said. “We want time to fully review the report first. One of the most important purposes of this study was to serve as a baseline for future studies.”

NRG Energy, owners of the Indian River Power Plant have shut down two of its four coal-fired generating stations; the third unit is set to be shut down later this year.

NRG has implemented $361 million dollars to install state-of-the-art emissions control systems on Unit 4, after a previous investment of $51 million on both Units 3 and 4, said David Gaier, NRG's director of communications.

"These investments make Indian River one of the cleanest, if not the cleanest, coal plants in the United States," Gaier said.

Holistic nutritionist and a member of Citizens for Clean Power, Dr. Kim Furtado said the study does not accurately portray the types of exposure experienced by residents. Furtado said exposure from the power plant would have come in low doses over a long period of time.

“The testing methods used by the state are best suited for acute, high-dose exposures,” Furtado said. “It is not surprising they did not find elevated levels, because they did not perform the appropriate body burden assessments to look for chronic low-dose exposure.”

Furtado said exclusion criteria could have prevented volunteers who have only lived in the Millsboro area for a few years from participating in the study. She said toxics in the body build up over time, so newer residents would not have had as much of an effect from the pollution as older residents.

She said this criteria is especially important when the sample size is small. For example, a person that moved to Millsboro the week before the study started could have been included, Furtado said.

Although it is controversial, Furtado said said the study should have included a provoked urine test, which in some cases is a better measure of toxic metals and mercury than a normal urine test.

“These limitations severely hinder the study's capacity to find any meaningful information," Furtado said.

Furtado shared her concerns with RTI consultants in 2008, and RTI made four recommendations on ways to incorporate a provoked urine test to the Delaware Department of Health and Social Services and Delaware Department of Natural Resources and Environmental Control. In the end, provoked urine testing was not included in the study.

“The obstacles to implementation of my suggestions were not insurmountable, but required expertise and dedication that DPH did not possess,” Furtado said. “All in all, I would say this study is 'much ado about nothing.'”

Knearl said the study was not to determine cause and effect relating to higher cancer levels surrounding Millsboro.

“The purpose was to improve our understanding of exposures of residents in Sussex County to fine particulate matter and associated inorganic species,” Knearl said. “The study focused on out of state, local, regional and local point sources that contribute to the overall exposures of the residents.”

She said the study did not look at other ways chemicals from the power plant could have entered people's homes such as through water or soil.

Delaware Department of Natural Resources and Environmental Control spokeswoman Carol Riggs said the department has not had time to analyze the results of the study. She said comments will be made when the report is presented May 21.

Delaware Cancer Consortium Environmental Subcommittee chairwoman Meg Maley did not return requests for comment.