Spring is allergy season and as I made my customary trip to the farmers market to stock up on local wild flower honey this last weekend, I could not help but notice the honey stand was considerably smaller than I remember it in past years. In addition, the price of honey was at least 20% higher, if not more. My thoughts turned to the cause of this problem: the dying of these diligent pollinators, how this affects the food chain, and, of course, what chemists can do to help. I started to wonder if sample preparation techniques, such as the Accelerated Solvent Extraction (ASE) technique could be used to extract pesticides from bee-based products, such as bee pollen. But, before I talk about analytical techniques, I thought I would give a brief overview on what is going on with bees and pesticides.
Bee Colony Collapse Disorder
A recent blog article posted in Scilogs titled, Spring is Here but Where are all the Bees? - The latest on Colony Collapse Disorder (CCD) discusses bee colony collapse disorder and the wide use of a class of insecticides, neonicotinoids, which are causing the largest number of honey bee deaths. Neonicotinoids cause bees to behave mysteriously and makes bee colonies descend into chaos during the worst season for the insects to be active: winter. During the winter seasons, a colony affected with CCD dissolves, with the hive's workers leaving the hive, only to die in the unforgiving winter. The European Union banned neonicotinoids in 2013 and in the United States; the Environmental Protection Agency (EPA) is unlikely to approve new neonicotinoid pesticide use as it continues to assess pesticide safety for bees. The toxicity of neonicotinoids to bees and other insects has brought them the most attention thus far and has dominated recent concerns of regulatory institutions worldwide. The serious risk to bees should not be understated, as one-third of the U.S. diet depends on these insect pollinators. The American Bird Conservancy (ABC) assessment makes clear, however, that the potential environmental impacts of these pesticides goes well beyond bees. Their report urges EPA to expand its registration review of neonicotinoids to include birds, aquatic invertebrates, and other wildlife.
Pesticides are classified into groups based on their chemical structure (organophosphates, pyrethroids, organochlorines, carbamates, neonicotinoids etc.), mode of action (systemic, contact), target (insecticides, acaricides, herbicides, fungicides, bactericides, nematicides) and synthesis (synthetic or natural). The residues of pesticides detected in products are classified in the groups of insecticides (organochlorines, organophosphates, carbamates and neonicotinoids), acaricides, fungicides and herbicides. Organochlorine pesticides are persistent organic pollutants (POPs), a class of chemicals that are ubiquitous environmental contaminants because they break down very slowly in the environment and accumulate in lipid rich tissue such as body fat. Many organochlorine pesticides are endocrine-disrupting chemicals, meaning they have subtle toxic effects on the body’s hormonal systems.