Insecticide Risk Drivers U.S. (IRD-US)

The IRD-US accompanies the publication “Insecticide Risk in US Surface Waters: Drivers and Spatiotemporal Modeling” published in Environmental Science & Technology. All plots presented here are interactive reproductions of figures in the main text. Please refer to the publication via the following link for detailed methodological descriptions. Briefly, measured insecticide concentrations (MIC) were compared to their regulatory threshold levels (RTL), generally referred to as MIC to RTL ratios, for various scenarios. MIC to RTL ratios (log10-transformed) greater than 0 represent insecticide concentrations or mixtures exceeding regulatory threshold levels, suggesting that aquatic biota are adversely affected. Aforementioned ratios greater than -1 reflect exceedances of biodiversity thresholds, suggesting a loss of local biodiversity in affected streams or lakes (see publication). All MIC to RTL ratios depicted here were log10-transformed.

An interactive map, detailing the spatial exceedance probabilities of RTLs derived via modeling, can be found here.

Figure o1a

MIC to RTL ratios for surface waters (blue) and their sediments (brown) with their median (dot), their corresponding 95% CI (black error bars). RTLs are depicted with a solid line (red) and biodiversity thresholds are represented by dotted lines.

Figure o1b

MIC to RTL ratios for surface waters (blue) with their median (dot), their corresponding 95% CI (black error bars) and smoothed distributions (violin plots). RTLs are depicted with a solid line (red) and biodiversity thresholds are represented by dotted lines. Annotations detail RTL exceedance frequencies (%) per respective group.

Figure o1c

MIC to RTL ratios for sediments (brown) with their median (dot), their corresponding 95% CI (black error bars) and smoothed distributions (violin plots). RTLs are depicted with a solid line (red) and biodiversity thresholds are represented by dotted lines. Annotations detail RTL exceedance frequencies (%) per respective group.

Figure o2a

Cumulative frequency distributions of MIC to RTL ratios determined for insecticide mixtures for surface waters. Frequency distributions using sole MIC to RTL ratios (i.e., those not occurring in mixtures, black) are compared to distributions of mixtures either using only the most toxic component (maxTU) in violet and the sum of all components (sumTU) in green. RTLs are depicted with a solid line (red) and biodiversity thresholds are represented by dotted lines.

Figure o2b

Cumulative frequency distributions of MIC to RTL ratios determined for insecticide mixtures for sediments. Frequency distributions using sole MIC to RTL ratios (i.e., those not occurring in mixtures, black) are compared to distributions of mixtures either using only the most toxic component (maxTU) in violet and the sum of all components (sumTU) in green. RTLs are depicted with a solid line (red) and biodiversity thresholds are represented by dotted lines.

Figure o2c

Cumulative frequency distributions of MIC to RTL ratios determined for insecticide mixtures for surface waters and sediments (i.e. both compartments combined). Frequency distributions using sole MIC to RTL ratios (i.e., those not occurring in mixtures, black) are compared to distributions of mixtures either using only the most toxic component (maxTU) in violet and the sum of all components (sumTU) in green. RTLs are depicted with a solid line (red) and biodiversity thresholds are represented by dotted lines.

Figure o3a

Median MIC to RTL ratios of maxTUs (dot) with their 95% CIs (bars) of surface waters (blue) for different catchment size classes in km². Individual MIC to RTL ratios (black), as depicted in Figure 1b, are provided for comparison purposes.

Figure o3b

Median MIC to RTL ratios of maxTUs (dot) with their 95% CIs (bars) of sediments (brown) for different catchment size classes in km². Individual MIC to RTL ratios (black), as depicted in Figure 1c, are provided for comparison purposes.