Figure 4
Average pollen sample risk quotient at each farm where pollen was collected from honey bees in 2018 (triangles) and 2019 (squares) and bumble bees in 2019 (circles). Contact (x-axis) and oral (y-axis) LD50 values were used to calculate risk quotient using Apis mellifera toxicity values for honey bee pollen, and Bombus terrestris values were used whenever possible for bumble bee pollen. RQ is displayed in relation to the EPA and EFSA levels of concern (proportion of the LD50). The green dashed line is the EFSA level of concern (LOC) for chronic oral exposure (0.03). The blue dashed line is the EFSA level of concern for acute exposure (0.2), and the red dashed line is the EPA level of concern for acute exposure (0.4). However, EPA and EFSA do not use acute LOCs for oral exposure. These are included on the y-axis for illustrative purposes only. Graph created in R version 4.1.147 with the package ggplot2110.
