Poor air quality raises mortality in honey bees, a concern for all pollinators.

Human well-being relies on the presence and role of pollinators, as they contribute to the vitality of ecosystems, support the reproduction of wild plants, increase crop yields, and strengthen overall food security. While wild bee populations are dwindling due to climate and environmental change, there has been a notable 45% rise globally in the number of managed honey bee (Apis mellifera) colonies over the past five decades. Given their economic significance and their relative ease of tracking, honey bees have the potential to serve as bioindicators of global pollinator health. Consequently, honey bees have emerged as a keystone species requiring protection and conservation efforts. Here, we investigate the intricate relationship between air quality, environmental factors, and honey bee mortality across Canada and the United States. Using statistical and machine learning modeling, our findings underscore the honey bee's role as a bioindicator. We found that air quality is an important predictor of honey bee mortality. The risk of honey bee mortality increased with poor air quality (ozone and Air Quality Health Index) but was substantially reduced in regions with greater vegetation availability (Normalized Difference Vegetation Index). Therefore, our study offers a beacon of hope: improving management practices by increasing greenery can significantly mitigate the impact of deteriorating air quality on honey bees, providing a vital solution to safeguard our essential pollinators.