Assessing health risks for the Darling Downs rural sector due to consumption of potentially impaired (Herbicides) drinking water - Executive report

Assessing health risks for the Darling Downs rural sector due to consumption of potentially impaired (Herbicides) drinking water - Executive report

Pesticides are considered hazardous chemicals that pose potential health risks upon exposure, either acutely in high doses or chronically in low doses. Drinking contaminated water is one of the ways of chronic exposure to low doses. This occurs due to herbicide leaching from agricultural lands to the groundwater (which varies according to soils and rocks properties) and has been reported in many areas worldwide. Environmental agencies have provided threshold values for exposure doses and concentrations; when herbicides concentrations in groundwater exceed these values, potential health risks intensify.

Herbicides have never been monitored in the Darling-Downs groundwater. However, it has been detected many times in the Condamine River, which drains the same agricultural areas. These findings, the proximity of domestic bores to the fields and the general heavy use of herbicides for the area’s major crops (cotton), potentially increases the exposure, risk and health impacts in the local population.
As a first step to address these concerns, A pilot water-quality study was conducted during February 2015 near Ellangowan, SE Queensland. The study comprises 12 bores (domestic, irrigation and monitoring) in a relatively small locality. Groundwater samples were analyzed by accreditae labs for general composition and herbicides. The latter includes 50-54 analytes (Appendix A). In additions, while collecting the water sampling, the local participants filled out questionnaire regarding pesticides use and water quality.

The findings are generally encouraging (see following section), and dismissed any major concern regarding regional exposure to herbicides due to drinking the underground water. It can be concluded that despite the intensive farming, the potential leaching of herbicides to the groundwater table in the studied area is low. Nevertheless, local actions can contribute to different results in individual bores.

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