A Cause For Concern?

Another study has attempted to link pesticide use with increased cancer rates, but many believe these claims are unsubstantiated.

Results from the Newton Breast Cancer Study, released to the public in October 1999, have heightened concerns for some about a link between environmental factors and breast cancer, but ultimately the study has raised more questions than it has answered.

Initiated as follow-up to research done by the Massachusetts Department of Public Health (MDPH) and conducted by the independent Silent Spring Institute (SSI), the study found that cancer rates among women from Newton, Mass., were higher in areas where women were affluent, well educated and had regular mammography screenings. Newton was chosen by the MDPH because its breast cancer rate was 13 percent higher than the statewide rate.

The study was based on responses from about 1,350 Newton women (ages 35 to 75) to a questionnaire about their health history, individual characteristics, habits and home environments. The research evaluated areas of high and low incidence in Newton, ranging from 22 percent below to 55 percent above the statewide rate from 1982-92.

The study found that 65 percent of the women in the areas with higher breast cancer rates had used a professional lawn care service, compared with 36 percent of the women in the lower-incidence neighborhoods.

In addition, it found that 30 percent of the women in high-incidence reas routinely used pesticides, compared with 23 percent of the women from low-incidence areas.

NO DEFINITIVE ANSWERS. While these findings could be cause for concern, many question the study’s validity because of its narrow scope. Particularly troublesome for those in the pest control industry is the fact that the study only covered a very small region and it was based on surveys as opposed to being conducted by an epidemiologist.

"The study was largely anecdotal and it did not have a large sample," said Gene Harrington, manager of government affairs, National Pest Management Association (NPMA). "It was similar to work done in Long Island that gave rise to bad legislation there."

Bob Rosenberg, director of government affairs, NPMA, added that there have been many more studies conducted using larger sample populations in which pesticides deemed carcinogenic were proven noncarcinogenic. "Studies done by one small group are really of no value," he said. "The better studies are the ones which are done on the state and federal level. If the products used in pest control were found to cause adverse health effects then we would certainly want to find other products to use, but there is no evidence to suggest an association with the regular and proper use of pesticides and increased cancer rates."

The MDPH has even conceded that no conclusions can be drawn from the Newton Breast Cancer Study. For each of the factors that differentiated the rates between women in high- and low-incidence areas "it is not known from this study if they carry any breast cancer risk," according to MDPH.

Further, MDPH stated that higher socioeconomic status itself does not cause breast cancer; instead, it is believed that it may be a proxy for some factor(s) characteristic of the behaviors or exposures of these individuals.

It is also important to note that other significant findings from the study point to non-environmental factors for increased cancer rates. For instance, the study reported that women in higher socioeconomic areas of Newton had regular mammography screenings and thereby widespread early detection of breast cancer was prevalent among this group. According to the study, 27 percent of the women in the high-incidence area said they had 10 or more mammograms, compared with 17 percent of the women from the low-incidence area.

WHAT LIES AHEAD? MDPH has determined that results from studies such as the Newton Breast Cancer Study are significant enough to warrant further investigations into links between breast cancer and environmental risk factors.

In fact, MDPH is currently funding a breast cancer study being conducted by SSI on Cape Cod, Mass., that has just entered its second phase.

Phase one of the Cape Cod Breast Cancer and Environment Study was similar to the Newton study in that it raised the possibility of a link between breast cancer and environmental risk factors and its findings were based on patterns and data analyzation.

Phase two includes a case-control epidemiologic study of about 2,500 women on Cape Cod. The case-control study will investigate the role of established risk factors, selected lifestyle factors and environmental factors.

Despite the fact that no conclusions can be drawn based on the results from both the Cape Cod Breast Cancer and Environment Study and the Newton Breast Cancer Study, when these reports are released to the public, the industry’s image is dealt another blow. And the more negative publicity that pesticide use receives, the greater the probability that an anti-pesticide movement can be sparked at the grass-roots level.

"The significance is that if a core of people believe that they or their family members or friends are getting sick from pesticides, it motivates and commits people to a cause," Rosenberg said.

To combat negative publicity that could be spawned from a report like the Newton Breast Cancer Study, Rosenberg recommends that PCOs stress to customers that pest management is one of the most highly regulated industries and the products they use and services they provide are highly regulated as well.

The author is associate editor of PCT magazine. He can be reached at bharbison@pctonline.com.

Results from the Newton Breast Cancer Study revealed that women from high-incidence areas of Newton, Mass., as a result of their personal habits or activities, had more contact with environmental factors than women from low-incidence areas. However, one result from the study that is inconsistent with the other findings was that 42 percent of women from low-incidence areas responded that they had used flea or tick products on pets as opposed to 36 percent of the women from high-incidence areas.

Key differences between respondents in the high-and low-incidence areas of Newton included:

High Incidence Area

Used termite control products 17%

at least three times as an adult

Used lice control products 22%

at least three times as an adult

High routine use of pesticides 30%

Ever used a professional lawn service 65%

Played golf 6%

Low Incidence Area

Used termite control products 9%

at least three times as an adult

Used lice control products 15%

at least three times as an adult

High routine use of pesticides 23%

Ever used a professional lawn service 36%

Played golf 3%