Air Pollution Found to Be Harming Health of Wild Pollinators

A giant Asian honeybee gathers pollen from a touch-me-not. (By © 2010 Jee & Rani Nature Photography. License: CC BY-SA 4.0)

(CN) — A recent study shows that air pollution poses a threat not only to humans but to many other organisms of the world including our key pollinator, the honeybee.

According to the World Health Organization, 9 of the 10 most polluted cities worldwide are now in India, making life difficult for the locals as well as the nearby wildlife. Pollution in the wild has been known to cause behavioral, neurological and reproductive deficits in animals, whether it be from the harmful particles in the air they breathe or contamination of food and water resources.

A study published Monday in the journal Proceedings of the National Academy of Sciences looked at how air pollution affects the giant Asian honeybee, Apis dorsata, which is an invaluable member of the surrounding ecosystem.

The largest of the honeybee species at just under an inch long, the critter lives throughout Southeast Asia and is indescribably important to the local floral and faunal diversity. The bee is responsible for 80% of India’s honey and the pollination of over 600 plant species. Without them, the country would not only see a massive decline in the production of popular fruit and vegetable exports and be in danger of serious food insecurity.

A team of scientists from the Bangalore Life Science Cluster sought to achieve a clearer understanding of the effects of global air pollution on nature and looked at Asia’s most valuable pollinator for answers. They observed more than 1,800 bees over the course of four years and uncovered a pattern of negative side effects associated with pollution. They found that the giant Asian honeybees pollinated far fewer flowers in highly polluted areas of Bangalore, consistent with previous research on the topic. This is because air pollutants can interfere with the scent molecules released by plants that attract bees, making the bees slower at finding food and pollinating.

The bees from more polluted places were also less healthy, showing deficits in heart rhythm, blood cell count, and overall less resilience to illness. They saw similar outcomes when they ran the same tests on fruit flies, proving that this was not an isolated phenomenon.

“The study was done with wild bees naturally visiting flowers in Bangalore city and not in lab assays on reared honeybees kept in hive boxes that may already be stressed or immuno-compromised,” said Dr. Hema Somanathan, expert in bee behavior and pollination ecology at the Behavioral and Evolutionary Ecology (BEE) Laboratory, Indian Institute of Science Education and Research, Thiruvananthapuram. 

“Thus, in my opinion this study provides us with hard evidence that all is not well with our wild bees. Given the scale of landscape alteration and urbanization in India, it is expected that these effects are widespread and likely to worsen with time,” Somanathan continued.

The authors said a shocking 80% of all the bees they collected died within 24 hours of acquisition from more polluted areas, similar to predictions made by the WHO. 

“So far, much of the air quality studies in India have either considered sources of pollution or impact on human health, and to an extent on economic productivity,” said Arunabha Ghosh, founder and CEO of the Council on Energy, Environment and Water, in response to the death rate of collected bees. “This study covers important new ground, by examining the impact of air pollution on pollinators, which would have serious implications for agricultural output in India. Such findings further underscore the need to raise India’s ambient air quality standards.” 

Latest research shows that during the Covid-19 pandemic, India’s notorious air pollution has significantly cleared following a massive lockdown. All flights, trains, and most factories shut down, and as a result harmful air pollution in New Delhi dropped by nearly 60%, according to the Centre for Science and Environment. More research will be needed to know how this improvement has affected the wildlife, but experts say that the clear skies above India right now show that change is possible.

“Better application of research and evidence in development policy-making can save lives, reduce poverty, and improve quality of life. In the case of this study, the research speaks for itself,” said Shloka Nath, executive director at the India Climate Collaborative and the head of sustainability and special projects at Tata Trusts.

“We now have concrete proof that by polluting our air, we are not only endangering our own health, we are also affecting the wild animals and plants who depend on it for sustenance. This has far-reaching implications for the complex ecosystems we are part of, as these changes affect the quality of habitat and food sources we all depend on,” Nath said.

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