by Pesticide Action Network North America
On February 8, 2005, national and state farm
highlighted some very disturbing medical monitoring results in
State. Their report, "Messages from Monitoring," looks
at the first year
of data from a Washington State program that tests farm workers
regularly handle organophosphates (OPs) and carbamates (CBs),
which are neurotoxic pesticides. The report shows that one in
tested experiences significant inhibition of cholinesterase--an
essential to proper nervous system function--and faults both state
federal agencies for failing to protect farm workers.
For nearly 20 years, farm workers in Washington have pressed
medical monitoring program, similar to a program instituted in
California, which has the only other monitoring program for this
toxic class of pesticides. After a state Supreme Court ruled for
workers, testing began in Washington at the start of the 2004
season. The Washington program applies to all workers who mix,
apply, or otherwise handle highly toxic OP or CB pesticides for
50 or more
hours a month.
When exposure to OPs or CBs causes declines in cholinesterase
workers can suffer serious health effects such as nausea, headaches,
fatigue, and seizures. If levels decline further more severe effects
occur, including long-term memory loss, paralysis and death.
Workers received "baseline" blood tests prior to the
spray season to
identify normal levels of cholinesterase. They then received monthly
follow-up tests when they met or exceeded the 50-hour per month
threshold. (That threshold drops to 30 hours per month in 2005.)
the monitoring rules, when cholinesterase levels decline by more
from the workers' baseline level, employers are required to conduct
workplace audits to identify and address factors contributing
depression. When levels decline by 30% or more in red blood cell
or 40% or more in blood plasma tests, workers must be removed
handling tasks until their cholinesterase levels rebound sufficiently.
Employers can reassign workers to other tasks that do not involve
significant exposures if available, and must maintain full salaries
for removed workers.
Over the course of the spray season, 123 (21%) pesticide handlers
of 580 who received both baseline and follow-up tests had depressions
more than 20% (the workplace audit level). Of these, 26 (over
4% of the
580 workers) had depressions low enough to trigger removal under
Four pesticides were repeatedly involved in serious depressions:
chlorpyrifos (Lorsban), azinphos methyl (Guthion), carbaryl (Sevin)
formetanate (Carzol). The majority of handlers needing removal
cholinesterase depressions used a mixture of carbaryl and an OP
(chlorpyrifos or azinphos methyl). One common contributing factor
workplaces with depressions was the use of air-blast sprayers
tractors to apply the pesticides.
Significantly, in a large percentage of the serious depression
there was no evidence of non-compliance with federal Worker Protection
Standards or pesticide labels. Many case summaries, in fact, noted
growers and their employees exceeded regulatory requirements by
a respirator for chlorpyrifos though this is not required. The
notes that EPA's own analysis predicted that occupational exposures
would pose unacceptable risks, "In fact, citing cost-benefit
federal pesticide registration law, EPA has approved continued
some highly toxic OPs while openly acknowledging that even with
Personal Protective Equipment (PPE) and engineering controls,
experience exposures which EPA considers unacceptable, i.e. having
Margins of Exposure (MOE) less than 100. Almost all handling scenarios
azinphos methyl pose exposure risks for workers which EPA considers
unacceptable, and numerous scenarios for chlorpyrifos do the same."
"Messages from Monitoring" identifies serious problems
Washington testing that may mask evidence of even greater harm.
statistical analyses done by the program's Scientific Advisory
reveals the risks of false negatives may be as high as 50%. The
Committee also noted that many depressions might have been missed
the length of time that elapsed between sample collection and
In other cases, workers reportedly declined monitoring due to
perceived employer interference.
The report also faulted the Washington State Department of Labor
Industry (L&I) for its slow response when testing revealed
declines. "L&I chose not to use its enforcement authorities
investigate workplaces where depressions occurred. Even in cases
workers had depressions, the agency adopted a 'consultation' approach."
The average interval between receiving test results and performing
workplace audits or removals was more than 7 days, during which
workers may have been receiving additional exposures.
"Messages from Monitoring" points out that the Washington
program tests pesticide handlers, and not field workers despite
body of literature demonstrating routine pesticide exposure among
workers and their families. Finally, the report faults government
failing to promote alternatives to these dangerous pesticides,
on state agencies and the federal government to end the use of
risky pesticides, including azinphos methyl, chlorpyrifos and
highly toxic OPs and CBs, and to require cholinesterase monitoring
The United Farm Workers of America, AFL-CIO (UFW) is now circulating
online petition asking EPA to implement a national cholinesterase
monitoring program. To sign the petition visit:
Source: "Messages from Monitoring," Farm Worker Pesticide
Farmworker Justice Fund, United Farm Workers, http://www.fwjustice.org.
Contact: Farm Worker Pesticide Project, 206-729-0498, PANNA.