EPA Science Advisory Panel Meets to Discuss Atrazine

A Science Advisory Panel (SAP) supporting EPA’s Office of Pesticide Programs met this week to consider issues related to the health effects of atrazine and how the monitoring scheme impacts the estimation of risk.  This SAP activity is in support of a reevaluation of the health risks of atrazine.   On the health effects side, the duration of exposure and the timing of exposure seem to be the critical factors for the health effects from drinking water.  Short term exposures to elevated levels of atrazine may be more important in triggering the health effects than long term exposure to lower levels.  Therefore, when considering the monitoring results, the timing of monitoring during the year and the sampling frequency are critical.  In spite of one of the most robust sets of monitoring data for any pesticide, it is still difficult to come up with the exact information needed to characterize exposure.  The group considered how models and statistical methods could be used to “in fill” the gaps in monitoring data to provide better exposure estimates.  Although this evaluation is far removed from any modifications of the regulatory requirements, it indicates how critical the frequency of monitoring is to the estimation of risk and may point to a different monitoring scheme than is prescribed now for atrazine.

The work of the SAP can help EPA develop an appropriate monitoring scheme for atrazine in the future and may serve as a model for other pesticides.  Details about the specific questions the SAP is charged to answer and presentations that were shared at the meeting are available through the SAP website.