Findings suggest human health risks from inhaling pollen laced with neonicotinoids
FRISCO — Scientists with Harvard University’s T.H. Chan School of Public Health say their new study examining pollen and honey shows there’s a need to develop public policies that aims to reduce neonicotinoid exposure.
After working 62 Massachusetts beekeepers who volunteered to collect monthly samples of pollen and honey from foraging bees, the researchers found more that 70 percent of the samples contained at least one neonicotinoid, a class of pesticide that has been implicated the steep decline of honeybee populations, specifically colony collapse disorder, when adult bees abandon their hives during winter.
The study will be published online July 23, 2015 in the Journal of Environmental Chemistry. Not only do these pesticides pose a significant risk for the survival of honey bees, but they also may pose health risks for people inhaling neonicotinoid-contaminated pollen, Lu said.
“Data from this study clearly demonstrated the ubiquity of neonicotinoids in pollen and honey samples that bees are exposed to during the seasons when they are actively foraging across Massachusetts,” said Chensheng (Alex) Lu, associate professor of environmental exposure biology. “Levels of neonicotinoids that we found in this study fall into ranges that could lead to detrimental health effects in bees, including CCD,” Lu said.
Since 2006, there have been significant losses of honey bee colonies. Scientists, policymakers, farmers, and beekeepers are concerned with this problem because bees are prime pollinators of roughly one-third of all crops worldwide.
In this study, the researchers looked at pollen samples collected over time — during spring and summer months when bees forage — from the same set of hives across Massachusetts. That enabled the scientists to determine variations in the levels of eight neonicotinoids and to identify high-risk locations or months for neonicotinoid exposure for bees.
The researchers analyzed 219 pollen and 53 honey samples from 62 hives, from 10 out of 14 counties in Massachusetts. They found neonicotinoids in pollen and honey for each month collected, in each location, suggesting that bees are at risk of neonicotinoid exposure any time they are foraging anywhere in Massachusetts.
The most commonly detected neonicotinoid was imidacloprid, followed by dinotefuran. Particularly high concentrations of neonicotinoids were found in Worcester County in April, in Hampshire County in May, in Suffolk County in July, and in Essex County in June, suggesting that, in these counties, certain months pose significant risks to bees.