New Blood Test Depicts Exposure to Pesticides

A simple, fast, and inexpensive blood test accurately detected the level of exposure to potentially harmful pesticides among agricultural workers, according to a NIOSH-funded study at Washington State University in Pullman, Washington, and the University of Washington in Seattle. The study appeared in the journal Biosensors and Bioelectronics.

Pesticides are a common agricultural aid that can help increase harvests. The problem is that over-exposure to some pesticides can cause serious health problems such as nerve damage, so worker protection, including exposure monitoring, is critical. At NIOSH, the Pesticide Surveillance Program monitors work-related illness and injury from exposure to pesticides.

Currently-available tests for exposure monitoring are expensive, time-consuming, and require special equipment and trained personnel. To address this issue, the scientists created and verified a simple, inexpensive blood test that could be used to quickly diagnose exposure among agricultural workers.

The so-called sandwich ELISA test is unique in its ability to measure the level of immune response-triggering molecules or antigens. Much like the commercially available pregnancy tests, this test comprises a treated strip that reacts in the presence of specific protein molecules, or enzymes. In this case, the treated strip changed color in the presence of enzymes produced by the liver after exposure to phosphorus-based pesticides.

To verify the test’s accuracy, the scientists measured the level of pesticide exposure in 124 blood samples from study participants who had worked with pesticides in orchards or on cotton farms in Washington State or Pakistan. They found that the test accurately and quickly measured pesticide exposure by detecting pesticide-related enzyme activity and the total amount of enzyme in the blood.

With the goal of making the test commercially available, the scientists now are verifying its accuracy and developing software to enable its use in the field.