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Particulate and silica health risk research being conducted by Dr. Crispin Pierce and students in the Environmental Public Health Program has the following aims:

1.      Review previous research and exposure standards for environmental  and workplace exposure to "simple" or "nuisance" dust, particulate matter (PM10, PM4, PM2.5, and "respirable" dust particles), and crystalline silica (quartz).

2.      Record GPS coordinates, wind speed and direction, particulate matter (mass concentration and particle concentration), and crystalline silica concentration, and photograph locations surrounding Wisconsin sand mining, transporting and processing plants.

3.      Report measured particulate matter and crystalline silica concentrations and recommended exposure standards to the Wisconsin Department of Natural Resources, industry, concerned citizens, and the environmental health community (through conference presentations and peer-reviewed publications).
Fay, Kleist, Pierce Sampling - 7-11Fay and Nelson sampling -7-11
Faculty and students perform initial sampling upwind and downwind of the Chippewa Falls sand plant during construction on July 30-31.  Working with local landowners, the following data were collected: GPS waypoints, temperature, wind speed, wind direction, humidity, PM 2.5 particle concentration, respirable mass concentration, and respirable silica concentration (analyzed by the Wisconsin State Lab of Hygiene).


As of January 2013, Dr. Pierce and ENPH students have measured particulates around sand facilities six times, in summer and winter months.

Research Questions

We are using a Dusttrak 8520 aerosol monitor and an SKC DPS gravimetric monitor, and reviewing DNR- and industry-generated data to address the following questions:

1) Are particulate pollution levels around sand mining, transporting and processing plants above the EPA 35 microgram/m3 24-hour or 12 microgramg/m3 annual standards for PM2.5 (particles 2.5 micrometers and smaller)?

2) Are crystalline silica levels around these plants site above a nominal 3 ug/m3 exposure standard set by the State of California?

3) Which factors (windspeed and direction, degree of plant activity, precipitation, etc.) are associated with increased PM2.5 levels?

This study benefits from collaboration of UW-Eau Claire faculty and students with the Concerned Chippewa Citizens community group and the Wisconsin Department of Natural Resources.

Research Answers

A 1995 American Cancer Society study, 2002 follow-up, and published 2012 study of six cities found that each 10-microgram per-cubic-meter increase in long-term average PM2.5 concentration was associated with a 4-14% increased risk of death from all natural causes, a 6-26% increased risk of death from cardiopulmonary/cardiovascular disease, and an 8-37% increased risk of death from lung cancer. 


1) Our 1- to 5-minute multiple "snapshot" samples found that the measured levels of PM2.5/4 increased from EOG plant construction through full operation:

Measured EOG PM

2) Our Measured PM10 Levels During Operation Were Higher than the DNR Model-Predicted Maximum Concentration and the EOG 24-Hour Measured Levels:


3) EOG PM10 Measurements are Unreliable Estimates of PM2.5:

PM 2

4) Measured Levels of PM2.5 at EOG, Superior Silica Sands (Auburn), and Fairmount Mine (Menomonie) Were 1.7-22 micrograms/m3 Higher Than Concurrent DNR Regional Levels:


5) Measurement and Enforcement of the Current EPA 12 micrograms/m3 PM2.5 Standard is Likely to Protect Against Silicosis Risk


6) Snow, Wind and Degree of Plant Activity Appear to Influence Measured PM2.5 Levels:

Activity level