19 research outputs found
Variability of Pesticide Dissipation Half-Lives in Plants
Information on dissipation kinetics
of pesticides in food crops
and other plants is a key aspect in current risk and impact assessment
practice. This is because human exposure to pesticides is predominantly
caused by residues in agricultural crops grown for human and animal
consumption. However, modeling dissipation of pesticides in plants
is highly uncertain and therefore strongly relies on experimental
data. Unfortunately, available information on pesticide dissipation
in plants from experimental studies only covers a small fraction of
possible combinations of substances authorized for use on food and
fodder crops. Additionally, aspects and processes influencing dissipation
kinetics are still not fully understood. Therefore, we systematically
reviewed 811 scientific literature sources providing 4513 dissipation
half-lives of 346 pesticides measured in 183 plant species. We focused
on the variability across substances, plant species and harvested
plant components and finally discuss different substance, plant and
environmental aspects influencing pesticide dissipation. Measured
half-lives in harvested plant materials range from around 1 hour for
pyrethrins in leaves of tomato and pepper fruit to 918 days for pyriproxyfen
in pepper fruits under cold storage conditions. Ninety-five percent
of all half-lives fall within the range between 0.6 and 29 days. Our
results emphasize that future experiments are required to analyze
pesticide–plant species combinations that have so far not been
covered and that are relevant for human exposure. In addition, prediction
models would help to assess all possible pesticide–plant species
combinations in the context of comparative studies. The combination
of both would finally reduce uncertainty and improve assumptions in
current risk and impact assessment practice
Chronic hazard index (<i>CHI</i>) for each metal and metalloid at the three study sites.
<p>Chronic hazard index (<i>CHI</i>) for each metal and metalloid at the three study sites.</p
Average daily intake of heavy metals and metalloids by adults and children and the respective hazard quotients.
<p>Average daily intake of heavy metals and metalloids by adults and children and the respective hazard quotients.</p
Conceptual illustration of the fate pathways of mining-related emissions of heavy metals and metalloids in the environment potentially leading to exposures for human and ecological receptors.
<p>Conceptual illustration of the fate pathways of mining-related emissions of heavy metals and metalloids in the environment potentially leading to exposures for human and ecological receptors.</p
Heavy metal and metalloid contamination factors and ecological risk factors at the three tailings sites.
<p>Heavy metal and metalloid contamination factors and ecological risk factors at the three tailings sites.</p
Toxicological parameters for heavy metals and metalloids used in health risk assessment.
<p>Toxicological parameters for heavy metals and metalloids used in health risk assessment.</p
Concentrations of heavy metals and metalloids in samples of tailings contaminated soils.
<p>Concentrations of heavy metals and metalloids in samples of tailings contaminated soils.</p
Mean relative abundance of minerals identified in samples.
<p>Mean relative abundance of minerals identified in samples.</p
Distribution of pathways contributing to potential human exposure following an assumed emission of different heavy metals and metalloids of 1 kg per day to natural soil.
<p>Distribution of pathways contributing to potential human exposure following an assumed emission of different heavy metals and metalloids of 1 kg per day to natural soil.</p