Earlier this year, the Department of Ecology took 20 soil samples from Ballard and several other Seattle neighborhoods to test for pollutants such as dioxins and polycyclic aromatic hydrocarbons (PAHs).
The DOE has run its tests and concluded that Ballard has the highest level of PAHs in the neighborhoods it tested, although the numbers aren’t setting off any alarms. “The range of dioxin and PAH concentrations in the Seattle study are similar to the range of concentrations found in other urban areas,” the study release states. West Seattle had the lowest levels of PAHs and dioxins and Georgetown had the highest level of dioxins. “Dioxin levels are somewhat higher than those found in other cities,” according to the study release.
What exactly does this mean? Here is info from the Department of Ecology:
Overall, people’s exposure to dioxins and PAHs in Seattle neighborhoods’ soils is expected to be relatively small compared to exposure from other sources such as food (dairy and meat products especially), and compared to exposures that have been found to have harmful effects in people and animals. Soil, air and water usually contribute only a small part of our normal exposure to dioxins and PAHs.
People are normally exposed to dioxins and PAHs because they are present in many foods and throughout the environment. For nonsmokers, about 90 to 95 percent of exposure usually comes from food. Cigarette smokers may have a little extra exposure to dioxins, but their exposure to PAHs may be significantly higher, equaling or exceeding that from food.
Several studies found increased rates of cancer in people who for many years were exposed to dioxins in their workplace. Dioxins also may have specific harmful effects on the liver, peripheral nerves and the immune system. Several PAH-containing products – including tobacco smoke, coal tar and creosote – are known to cause cancer in people.
However, the amount of exposure in these studies was significantly higher than would occur from Seattle soils. While elevated levels of dioxins and PAHs in soil may slightly raise the risk of cancer, the risk can be reduced by taking actions to reduce contact with soil.
Washing hands after playing or working outside (especially before eating), preventing kids from eating dirt, washing toys that have been in contact with the soil and avoiding tracking dirt into homes are ways to reduce direct contact with soil. The fact sheet (.pdf) offers more prevention tips.
More information on this study can be found here.