HEALTH EFFECTS OF AIRBOURNE PARTICULATE QUARTZ IN IOWA

The International Agency for Research on Cancer (IARC) has deemed quartz a human carcinogen, based upon in vitro experiments in humans and animals, and OSHA currently mandates that all manufacturers of products containing over 0.1% quartz label their products as "probable human carcinogens." The EPA has been monitoring PM-10 data on a county-by-county basis in Iowa. Quartz is a large constituent of PM-10. There is a possibility that miners and farmers, who are exposed to high concentrations of quartz dust on a regular frequency, may develop lung cancer. This study will help to establish the relationship between airborne crystalline silica and respiratory conditions of 11 selected counties in Iowa.

The counties being analyzed are distributed in the eastern, western, northern, and south central part of the state, representing industrial and agricultural land usage. Data has been analyzed by using PM-10 information graphed against lung cancer death rates, chronic obstructive pulmonary death rates and pneumonia death rates, with all the rates being per 100,000 people. There is no correlation present from 1996 to the present between the PM-10 data and the respiratory illness data for those respective years. However, there does exist a weak correlation for chronic obstructive pulmonary disease and pneumonia deaths for 1990-1995 when comparing the death rates against the 2001 PM-10 data. To determine whether this reflects a possible time lag or statistical randomness, PM-10 filters from each county for the years showing a relationship between high PM-10 concentration and high incidence of respiratory illness will be collected. These filters will then be analyzed by X-ray Defraction (XRD) to ascertain the concentration of quartz in the PM-10 portion. Knowing the quartz concentration in the PM-10 will aid in determining if quartz is indeed contributing to the declining respiratory health of these areas.

Both medical and PM-10 quartz concentrations from this study will be compared with a similar study in Idaho, which along with Iowa is one of the five dustiest states in the U.S. Bedrock geology and percentage smoking population differ between the two states allowing for these two studies to possible represent end member conditions for examining this relationship in naturally dusty environments.