Analysis and Modeling of What Honey Bees (Apis Mellifera L.) Bring Back to the Hive and How that Affects the Health of the Hive and Humans

Apis mellifera L. populations are decreasing at an alarming rate. Over the past 20 years, the number of managed honey bee colonies has declined, and this decline has become a global concern. This study focuses on chemical stressors that are found to affect the bee population. We used direct sampling to examine the variation of pesticides and heavy metals concentrations in two different landscape contexts. Subsequently, we extrapolated the risk of these toxins’ residues on Apis sp. based on current literature. We found no spatial variation in metal concentrations in pollen and honey samples collected from urban and agricultural areas. Likewise, we observed no spatial variation in pesticide concentrations in pollen and honey samples collected from urban versus agricultural areas.

In addition to chemical factors, we studied the nutritional factor by investigating the effect of spatial variability on the amount of stored pollen and the floral diversity of in-hive pollen. Furthermore, we estimated the most abundant botanical families that will identify honey bees' protein-source preferences. The results indicated a spatial variation in Shannon-Weaver diversity, demonstrating a higher diversity index with a wider variety of pollen taxa collected from urban sites compared to the agricultural ones with a lower diversity index with less pollen taxonomic variety.

The alarming decrease in honey bees’ population urges researchers to investigate the factors that enhance the deterioration of bees’ population. A few models explained these factors individually. We designed a NetLogo model to assess multiple factors that would intensify the impact of the Colony Collapse Disorder phenomenon, by investigating the spatial variation of bees’ exposure to a distinctive environmental toxin and the quantities of these toxins in hive products. The model indicated that there were significant spatial variation effects on the pesticides and heavy metal concentrations in the accumulated pollen and nectar inside the beehive.

Pesticides and heavy metal accumulation in bees’ products are mainly caused by human activities, which can affect human health by their consuming contaminated honey. Based on the results of honey analysis for pesticides and heavy metals we performed in the first study, we decided to select one pesticide and a pesticide synergist along with the most two abundant heavy metals to investigate the synergistic effect of cytotoxicity and genotoxicity that would result from the interaction of one major pesticide in honey: Imidacloprid and a pesticide synergist: Piperonyl butoxide, and two major heavy metals in honey: Lead and Selenium, at the cellular level in mammalian cells, where we found different interactional effects of these compounds on cell survival, cell apoptosis, oxidative stress, and sister chromatid induction.