Air pollution’s impact on pollinators

Did you know that one out of every three bites of food you eat is dependent on pollinators to produce? The importance of pollinators in our lives should never be understated: 35% of the world’s food crops need pollinators to produce¹. Unfortunately, air pollution is impacting pollinator quantities all around the world which may lead to devastating impacts on our global food systems and landscapes if action is not taken. Read on to learn about how pollinator populations are impacted by air pollution, what actions we can take, and how we can protect ourselves and our health from air pollution.

What is a pollinator?

Pollinators are a group of essential animals and insects that perform pollination. This is when pollen grains are moved from male part (anther) of a flower to the female part (stigma). This allows plants to reproduce and is responsible for the production of seeds and fruit that humans and other animals rely on as a food source. Some plants do perform self-pollination or use vectors such as wind to reproduce².

Animal pollinators include birds, bats, flies, beetles, butterflies, moths, wasps, and small animals. However, arguably the most famous and the most important of these is the bee. These creatures all visit flowers to feed: they either drink the flower’s nectar or consume pollen, and when they do so, they transport pollen grains as they move from flower to flower.

The world’s flowering plants are heavily reliant on these animal pollinators to reproduce: 78% of flowering plants in temperate zones and 94% in tropical zones are dependent on animal pollinators³. As you have likely heard, pollinator populations are in decline, and while the issue is multi-faceted, air pollution is partially to blame.

Air pollution impacts pollinators’ behaviour and environments

According to several recent studies, honeybees that were exposed to petrol exhaust emissions (mostly containing nitrogen oxides which is a mix of particulate matter [PM], volatile organic compounds [VOCs], and heavy metals such as zinc and lead) experienced changes in their learning and memory behaviours. Specifically, exposed bees took longer to learn plant VOCs (these are not anthropogenic VOCs but rather those found in nature, an adaptation that allows bees to identify various plants), and they forgot the VOCs much quicker than they normally would⁴. Furthermore, another field study found that when recorded ozone and NOx levels are higher than recommended for sensitive habitats, pollinator visits to flowers are reduced by 83-90%⁵.

Why is this happening? Scientists are finding that air pollution makes it more difficult for pollinators to recognise, locate, and memorise their floral resources which impacts their ability to forage and, thus, pollinate. The presence of PM, specifically, makes it so that heavy metals, dust, and other fine particulates adhere to the fine hairs on pollinators’ bodies when they become electrically charged to attract pollen⁵.

The application of fertilisers and increased nitrogen deposits in the air is also impacting pollinators’ food sources. Higher levels of nitrogen in the atmosphere as a result of fertiliser application enables nitrogen-loving plants to flourish, inhibiting and outcompeting other plants that may not thrive as well in nitrogen-rich environments. This was observed in Denmark where the marsh fritillary butterfly, a pollinator that relies on a plant called devil’s-bit scabious as a food source, has begun experiencing population decline as a result of devil’s-bit scabious being outcompeted by plant species that are less sensitive to nitrogen⁶.

What does this mean?

With increased concentrations of air pollutants impacting pollination rates, we are left wondering about the future of our food systems. The following chart shows which of our food crops are the least and most heavily dependent upon pollinators:

Reference: Our World in Data

What can we do?

Here is a list of things that you can do in your garden to help support pollinators:

• Plant native and a variety of pollinator-friendly plants of different colours, shapes, and sizes
• Spread awareness about the importance of supporting pollinators
• Limit or avoid the use of pesticides
• Install bat boxes (remember: bats are super pollinators, too!)¹

With the future of our pollinators and food crops hanging in the balance, it is more important than ever to reduce our contributions to air pollution. Action must be taken now at both the individual scale and the national scale to ensure balance in nature for future generations.

On an individual scale

The majority of air pollution found in our environments is a result of transportation. Reducing our vehicle emissions can reduce the presence of air pollutants in our breathing air. Instead of driving your own vehicle to your destination, consider other options like carpooling, using public transportation, or, for a zero-emission solution, biking or walking. If you must use your vehicle, be diligent about never leaving the engine idling. Investing in an electric vehicle is also a great solution, though unfortunately, most electricity on the electric grid is produced using fossil fuels which contributes to air pollution. Also, small actions like turning off the lights when you leave a room can make a big difference.

On a national scale

We must demand our governments to take action on industrial air pollution. The WHO has set guidelines regarding the levels of emissions we should not exceed, but unfortunately, 99% of the world’s population breathes air that exceeds these guidelines. Leadership should be making decisions that favour renewable energies, supporting cleaner and more efficient transportation systems, set stricter regulations for industrial pollution, and make clean household fuels more available and accessible.

Protect yourself and your health with an air purifier

If you are already following the above suggestions and doing your best to reduce your contributions to air pollution, you may feel like you have no control over the quality of your breathing air. In addition to being an advocate for improved air quality and the pollinators that so desperately need it, the best step you can take is to protect your health from the dangers of air pollution by investing in an air purifier.

Indoor air is 5-7 times more polluted than outdoor air. Eoleaf’s air purifiers offer some of the most advanced air purification technologies on the market, allowing you to breathe air free of pollutants and contaminants at home and at work. Our devices contain 8 different filtration technologies that remove allergens, fine particle pollution, pathogens, and mould and spores from your breathing air, protecting you and your health from adverse health effects. Reach out today to find the perfect device for your space.

References

¹ United States Department of Agriculture. (2023). The importance of pollinators. USDA. Retrieved March 2, 2023, from https://www.usda.gov/peoples-garden/pollinators

² Pollinator Partnership. (2023). About pollinators. Pollinator.org. Retrieved March 2, 2023, from https://www.pollinator.org/pollinators

³ Ollerton J, Winfree R, and Tarrant S (2011) How many flowering plants are pollinated by animals?  Oikos 120:321-326.

⁴ R. J. Leonard, V. Vergoz, N. Proschogo, C. McArthur, and D. F. Hochuli, “Petrol exhaust pollution impairs honey bee learning and memory,” Oikos, vol. 128, no. 2, pp. 264–273, Jan. 2019, doi: 10.1111/oik.05405.

⁵ James M.W. Ryalls, Ben Langford, Neil J. Mullinger, Lisa M. Bromfield, Eiko Nemitz, Christian Pfrang, Robbie D. Girling, Anthropogenic air pollutants reduce insect-mediated pollination services, Environmental Pollution, Volume 297, 2022, 118847, ISSN 0269-7491, https://www.sciencedirect.com/science/article/pii/S0269749122000616?via%3Dihub.

⁶ Brunbjerg, A. K., Hoye, T. T., Eskildsen, A., Nygaard, B., Damgaard, C. F. & Ejrnaes, R. (2017). The collapse of the marsh fritillary (Euphydryas aurinia) populations associated with declining host plant abundance. Biological Conservation. 211, 117-124.

7 Ritchie, H. (2021, August 2). How much of the world's food production is dependent on pollinators? Our World in Data. Retrieved March 2, 2023, from https://ourworldindata.org/pollinator-dependence