excerpted from "Pesticide and Toxic Chemical News" November 2, 1994, page 26
DRINKING WATER REPORT RAISES "UNWARRANTED FEARS", CRITIC SAYS
Media reports to the contrary, the director of Heidelberg College's Water
Quality Laboratory said that the Environmental Working Group's TAP WATER BLUES
report represents the "most convincing evidence yet" that herbicides in drinking
water do not "pose a significant cancer risk". David Baker, director of the
Tiffin, Ohio, college's water program, presented an analysis of the EWG report
at an October 26 media backgrounder sponsored by the National Council on Farmer
Cooperatives.
Baker commended EWG for its assessment of the impact of agriculture on water
resources, adding that the Heidelberg lab was the source of the "third largest
data set" used by the group. He added, however, that the group's
misrepresentation of its own study results has raised "unwarranted fears"
regarding the safety of drinking water in the midwest.
In an effort to make the EWG data more "understandable" to the general media,
Baker said what the group calls "cancer risks" need to be considered as
"expected additional cancers per year for the affected population." Baker
presented a table which took EWG data and expressed them in a "more
understandable format", arriving at a percentage of lifetime cancers per state
due to herbicides in drinking water.
According to Baker, these data show that " in no state are herbicides
responsible for even one additional cancer case per year" in the population
assessed by EWG.
While acknowledging that cancer is a "major cause of death and disease" in the
U.S., Baker added that no information is available regarding fatality rates for
"herbicide-induced" cancers. In expanding on data presented in the EWG report,
Baker said the groups' data would suggest that in the 23% of the Midwest
population with the highest pesticide concentrations, the five herbicides
covered in TAP WATER BLUES account for "approximately 0.006% of the cancer cases
that would occur from all causes."
Noting that the EWG did not make any estimates of the "actual number of cancers"
that may result from the presence of herbicides in drinking water, Baker said
that the groups' comments on risk levels were relative to "benchmark risks" of
one in a million. By calling these risks "unacceptable" and saying that
herbicides in water pose "very significant health threats," the EWG "strikes
fear" into millions of Midwestern residents, Baker added.
He said that while efforts should be taken to "reduce cancer occurences",
focusing on the herbicides studied in TAP WATER BLUES is " not an efficient way
to do so."
Following his presentaion, Baker answered questions from the invited media. One
query addressed the need for herbicides studied by the EWG. Baker and NCFC
representatives noted that farmers were already "reducing" the amounts used.
They added, however, that "improvements in tillage techniques" permitted by the
use of these herbicides have yielded" environmental" benefits, including a 70%
drop in pesticide runoff.
Baker noted that the EPA considers runoff of heavy rains and other "acts of
nature" in assessing the impact of pesticide residues. While the herbicides
covered by the EWG report were designed to "break down", NCFC said, heavy rains,
and not pesticide use, cause leakages leading to pesticide runoffs.
Sorry for any typos,
Thomas J. Hoogheem, the man from Monsanto
tjhoog@ccmail.monsanto.com
Those who feel the EWG report is right or wrong should take some time to study
it. It is not the "same old thning". It contains the first ever careful,
actual-data based estimate of exposure of pesticides in surface waters. The
report breaks no ground in risk assessment methodology per se, just in the
accuracy and science-base of one half -- the estimates of exposure. EPA
experts welcome the report, and wished they had done it first. It was
a huge numbers-crunching job. Others will follow, and we will move quickly
toward even more accurate estimates of exposure. Some people won't like
the answers, but we have to make a choice as a society. Are we going to
base regulations on who can scream loudest or what data tell us. Industry
has got to learn to accept the consequences of "good" science when it
does not cut their way.
Re herdicides and erosion and conservation compliance -- good
point, and I agree that farmers working Highly Erodible Land (HEL) are
caught between a "rock and a hard place". No-till systems work well
in many instances, but are more dependent on herbicides, not greatly so
and when you correct for less runoff, the environment probably gains
relative to other intensive, tillage based options. Of course a longer
rotation on those lands, if it were profitable, would be a better solution.
But remember, the majority of herb. are used on non-HEL cropland in the wide
expanses of the cornbelt, where farmers have more options to balance
tillage, cultivation, and chemicals. Farmers who band herbicides and cultivate
once have been able to cut rates 50% to 75%, with better control.
People tell me the major reason for tillage on many midwestern
farms is to combat compaction. There are biological approaches to combating
compaction, which in extreme cases are the only ones which will work. Pursuing
these solutions raises a whole new set of trade-offs between chemicals and
management options. Most herbicides today restrict fall cover crop planting
options significantly, and the low-rate highly active a.i.'s often do so
in the spring as well. For such small amounts to work full season, they
have to be both very active and persistent. Chemical based weed control clearly
does more to restrict farmer rotation options than the commodity programs,
especially as percent of flex acres goes up. I suspect this will emerge as
an issue ion the next few years, as more farmers gain (bad) experiences
with trying to diversify land use, establish grassed waterways and filter
strips, etc, only to watch them whither and die.
Thanks for the comments.