Pesticide Toxicity Hazard of Agriculture: Regional and Commodity Hotspots in Australia

Abstract

While the need to reduce the impacts of pesticide use on the environment is increasingly acknowledged, the existing data on the use of agricultural chemicals are hardly adequate to support this goal. This study presents a novel, spatially explicit, national-scale baseline analysis of pesticide toxicity hazard (the potential for chemicals to do harm). The results show an uneven contribution of land uses and growing regions toward the national aggregate toxicity hazard. A hectare of horticultural crops generates on average ten times more aquatic ecotoxicity hazard and five times more human toxicity hazard than a hectare of broadacre crops, but the higher yields and incomes in horticulture mean that both sectors are similar in terms of environmental efficiency. Livestock is the sector with the least contribution to overall hazard, even when the indirect hazard associated with feed is considered. Metrics such as pesticide use (kg/ha) or spray frequency (sprays/ha), commonly reported in highly aggregated forms, are not linearly related to toxicity hazard and are therefore less informative in driving reductions in impact. We propose toxicity hazard as a more suitable indicator for real-world risk than quantity of pesticide used, especially because actual risk can often be difficult to quantify. Our results will help broaden the discussion around pathways toward sustainability in the land-use sector and identify targeted priorities for action.

Pesticide Toxicity Footprints of Australian Dietary Choices

“…Recently, a high-resolution (1.1 km 2 ), national-scale map of agricultural pesticide toxicity in Australia was created [38]. The data included 158 chemicals (86 herbicides, 42 insecticides, and 32 fungicides) applied in the production of 25 different crop and livestock commodities.…”

“…The data included 158 chemicals (86 herbicides, 42 insecticides, and 32 fungicides) applied in the production of 25 different crop and livestock commodities. Using these data and parameters from the USEtox impact assessment model [39], the human and ecotoxicological impacts of pesticide use in relation to the production of agricultural commodities in Australia were characterized [38]. The USEtox model was developed under the auspices of the UN Environment's Life Cycle Initiative [40], and it is widely used in life cycle assessment studies [41].…”

“…The third indicator was freshwater ecotoxicity, also expressed in comparative toxicity units (CTUe), reflecting potential species loss. The details of this model are available in the associated references [38,39].…”

“…As such, the data resource described above provided a broad coverage of most Australian foods. For items not produced in Australia to any significant extent, namely tea leaves, coffee beans, hops, palm fruit, cocoa beans and coconut, the method described above [38] was replicated to provide equivalent data.…”

Identifying and characterizing pesticide use on 9,000 fields of organic agriculture

“…Due to the number of different products and chemicals applied in our study area, we rely on pesticide use and coarse metrics of ecotoxicity based on the pesticide product label, which reflects the exceedance of toxicity thresholds to different endpoints. We acknowledge pesticide use may not always reflect potential environmental harm 37,38 , and even thresholds of toxicity cannot differentiate between the hazards posed by two chemicals that both exceed regulatory thresholds, but that differ in toxicity. We consider and discuss toxicity metrics and limitations throughout.…”