This UC Davis wind tunnel is helping agricultural engineers analyze the content of rice smoke.

Experiments were conducted in a wind tunnel at UC Davis, as well as in the field. Complete analytical results are not yet available. Further sampling and analysis will continue through 1991.

Prior to the fall burning season, tests were run in the UC Davis wind tunnel. It has the capability of simulating many of the wind and fuel conditions of actual field fires and allows quantitative assessment of emission rates, which can't be done in field sampling. High particle loading rates seen in the tunnel samples made inspection of the filters for fibrous silica difficult.

Two field burns were conducted with monitoring equipment during the fall burning season. Filter samples from these tests were still being analyzed as this report was being written.

Analysis by the state Department of Health Services has been delayed because the difference in the nature of the samples compared to standard asbestos samples has required extensive new methods development.

Additional field experiments will be carried out as burn allotments are made in spring and fall 1991. After final analytical protocols are developed, further wind tunnel sampling will seek to quantify emission levels and to isolate materials coming from the straw as opposed to those coming from the soil and other sources.