Lab Matters Summer 2017 | Page 22

environmental health / food safety

by Keith Wegner, MS, laboratory services section chief, Colorado Department of Agriculture; Gareth Horvath, laboratory director, Minnesota Department of Agriculture; Lucio Barinelli, PhD, technical director, water analysis laboratory, New Hampshire Public Health Laboratories; Susan Chabot, laboratory scientist IV, New Hampshire Public Health Laboratories; Thuy Nguyen, branch chief, US EPA Office of Pesticide Programs, Analytical Chemistry Branch; Robyn Randolph, MS, specialist, Food Laboratory Accreditation; and Sarah Wright, MS, senior specialist, Environmental Laboratories

The Federal Insecticide, Fungicide and Rodenticide Act( FIFRA) gives the US Environmental Protection Agency( US EPA) the authority to regulate the registration, distribution, sale and use of pesticides. All states except Wyoming have been granted primary enforcement responsibility for pesticide use / misuse violations by US EPA. To support enforcement, pesticide residue and formulation data are commonly generated at state agricultural laboratories, but in some states, the public health or environmental laboratory may have this responsibility. To better understand how pesticide testing varies by state and how these laboratories interact with US EPA, APHL discussed this topic with representatives from Colorado and Minnesota agricultural laboratories, New Hampshire Public Health Laboratories and US EPA’ s Analytical Chemistry Branch.

The New Hampshire Public Health Laboratories receives herbicide tank, concentrate and residue samples for testing in use / misuse investigations. Photo by Sue Chabot

How is your laboratory involved in pesticide testing?

Wegner: The Colorado Department of Agriculture Biochemistry Laboratory has a staff of 14 and analyzes just over 1200 samples per year for pesticide residues in cannabis, groundwater, surface water, vegetation, soils and miscellaneous matrices( clothing, animal / fish tissues, turf, etc.). The laboratory’ s pesticide testing methods are on the ISO 17025 Chemical Testing scope.

Horvath: The Minnesota Department of Agriculture Laboratory Services Division has 14 employees and processes an average of 2,409 samples per year for 119,981 analytes. The laboratory is divided into two sections: one that analyzes pesticide residues in susceptible streams and aquifers and another that supports departmental pesticide incident investigations including misuse, misapplication, human / animal exposure, drift, bee kills and spills. The water analysis unit of the laboratory employs three liquid chromatography tandem mass spectrometry( LC / MS / MS) methods to analyze for 110 pesticides and two gas chromatography tandem mass spectrometry( GC / MS / MS) methods to analyze for 40 pesticides. These are ISO / IEC 17025:2005 accredited. Other method accreditations that we hold are for analyzing unique combinations of target analytes and matrices that often do not have established methodologies. This might be a food or vegetation sample with pesticide drift from a compound not registered for use on that commodity.

Barinelli / Chabot: The New Hampshire Public Health Laboratories are accredited by The NELAC Institute. We have one fulltime employee to analyze approximately 200 pesticide samples per year(~ 400 analyses). We partner with the state’ s Pesticide Control Division to analyze use / misuse samples, complaints, label claim verifications and to conduct a few special projects. Matrices include pesticide concentrates, pesticide applicator tank samples, residues( vegetation and wipe samples) and water.

How has your laboratory’ s pesticide testing helped to improve public health?

Wegner: The laboratory’ s pesticide residue testing program and increased inspections have significantly reduced pesticide usage in cannabis grow operations. In fiscal year 2015-2016, this reduction was more than 30 %.

Horvath: Some direct human-pesticide exposure samples can be used for medical diagnosis and treatment. However, most pesticide data are used to identify or determine chronic exposure, and support regulatory actions or practices designed to minimize exposures.