Re: sanet-mg-digest V1 #924
Manale.Andrew@epamail.epa.gov
Fri, 26 Mar 1999 11:46:19 -0500
Re. the Rachel article: There is another problem with the Cal-EPA study if it
only involved taking air samples. Many of the pesticides Cal-EPA should be
trying to monitor (semi-volatile compounds) are notoriously difficult to capture
in air monitoring equipment. I supported a study some ten years ago that, even
with over a million dollars to spend, produced only limited data on pesticide
exposure for only a small number of pesticides. Most monitoring studies only
examine the particulate phase and ignore the gaseous--fine if the concern is
drift onto a neighbor's cropland, but not so good if the concern is exposures
that may occur miles away. Fogs and other weather conditions can also affect
the likelihood of exposures various distances away. A better and far cheaper
study would involve modeling emissions and their fate and transport using
monitoring data to calibrate the models. A strictly monitoring study for a
reasonably large airshed, given the cost and difficulty of taking enough air
samples and analyzing them so as to have enough data to draw statistically valid
conclusions, has a low likelihood at the outset of proving significant exposure
and is certainly not the best approach to estimating short and longer term
exposure unless the agency has many millions of dollars to spend and has the
best equipment and scientists involved.
To Unsubscribe: Email majordomo@ces.ncsu.edu with the command
"unsubscribe sanet-mg".
To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command
"subscribe sanet-mg-digest".
All messages to sanet-mg are archived at:
http://www.sare.org/htdocs/hypermail