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

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.