Pollution and Pollinators

By Amanda Plunkett, NAHA Certified Clinical Aromatherapist®

In the spring edition of the NAHA Aromatherapy Journal 2021.1, my article “The Making of Bee Bread,” highlighted the science behind why pollination is really plant sex. Plants have adapted over millions of years to find the perfect recipe to attract their reproductive aid, their pollinators, by their means of communicating through a blend of odoriferous compounds. The perfect recipe often comprises of hundreds of compounds. “Rose (Rosa [×] damascena) flowers contain over 300 essential oil compounds that contribute to the attraction of pollinators.”[1] The “recipe” greatly affects success in pollination. “1,8-Cineole, present in 60% of the scents of orchids analysed by Dodson et al., 8 was found to attract the greatest number of pollinator bees (70%). In comparison, eugenol, methyl salicylate and methyl cinnamate attract fewer species.”[2] This intimate relationship between pollinator and plant relies heavily on specific formulations and can easily be disrupted by varying factors and leads to many questions.  Have you ever wondered if pollution affect our pollinators?

To help with their sexual life, many plants mimic the pheromones of female pollinators to attract the males of that specific specialized species. Although daisies and lilies also pollinate through sexual mimicry, orchids remain the most studied. "Some orchid flowers mimic the receptive females of (usually) just one pollinator species. Males are attracted by the shape and odour of the flower, which resemble the virgin female bee, and transfer the pollinia during so-called 'pseudocopulation' with the flower labella."[3] Then, after pollination of a flower, orchids will lower certain compounds and increase others to mimic the pheromones that inhibit copulation in the female. This ensures that the male bee moves to another flower rather than repeating pollination, and the flower changes the “recipe” of these secondary metabolite compounds to communicate their needs.

Pollution in Numbers 

Many times, in discussing air quality and research, the term “ozone” is used. Ozone exists in the stratosphere (6-30 miles above Earth) to protect us from harmful ultraviolet (UV) sun rays. However, the troposphere where we live (0-5 miles above the Earth), creates harmful nitrogen oxides and other harmful compounds that damages living tissues of plants and animals. The Environmental Protection Agency (EPA) has updated national standards to 70 ppb (parts per billion)[4] and the World Health Organization (WHO) recommends lower than 60 ppb[5] for an 8-hour average. For perspective, in 2016, the Los Angeles area averaged 96 ppb[6] and with wildfires can reach 185 ppb.[7] In 2020, Texas reported that ten of its counties regularly violated the federal standards of 70 ppb.[8] These numbers are essential to understanding the environmental impacts of pollution.

How Pollution Affects Pollinators

Through modeling and lab-controlled experiments, researchers have found that pollution negatively impacts our pollinators through changing the “recipes” of the plant emitted odors as well as changing pollen output. Let us consider just a few examples:

β-myrcene is a primary component of ylang ylang (Cananga odorata), African basil (Ocimum gratissimum), hairy mountain mint (Pycnanthemum pilosum), and the common hyacinth (Hyacinthus orientalis) flowers for pollinators. This constituent can also be found in essential oils such as bay laurel (Laurus nobilis) leaf and lemongrass (Cymbopogon citratus). In an ozone-free environment, this essential oil component travels more than 3,000 ft.; yet at 60 ppb it travels only 1,000 ft.[9],[10]

α-pinene, a primary component of African basil (Ocimum gratissimum) flowers, hairy mountain mint (Pycnanthemum pilosum) flowers and rosemary (Salvia rosmarinus) leaves[11] survives forty hours in an ozone free environment. Sadly, it only lasted ten hours at 60 ppb and only one hour at 120 ppb.[12]

Honeybee foragers found β-caryophyllene, a sesquiterpene that gives carnation (Dianthus caryophyllus) its sweet scent,[13] lasted only ten minutes in an ozone-free environment. When the ozone rose to only 20 ppb, not even close to the federal requirement, it took 180 minutes (three hours).[14]

What do all these numbers mean? Pollution not only confuses the recipe for attracting pollinators, but pollinators have to spend longer looking for resources which limits how much they can provide for their families, if they are able to find the flowers at all since it reduces the “distance over which floral olfactory signals can be detected by pollinators.”[15] 

Once pollinators do find the food, pollution also negatively impacts the quality and quantity available for forage. With more time spent foraging, less energy is spent on pollination activity. This decrease in pollinator foraging efficiency could simultaneously decrease the pollinator's reproductive output and the amount of pollen flow in flowering plants. Plants, when exposed to ozone at 100 ppb, were seen to have a decreased pollen germination percentage and pollen tube length, as well as delayed flower development and increased bud abortion/abscission.”[16]

In addition to directly influencing foraging rates and foraging amounts, pollution may also contribute to reduced nectar and pollen availability by worsening droughts:

“Increases in air pollution and other particulate matter in the atmosphere can strongly affect cloud development in ways that reduce precipitation in dry regions or seasons, while increasing rain, snowfall and the intensity of severe storms in wet regions or seasons, says a new study. The research provides the first clear evidence of how aerosols can affect weather and climate, with important economic and water resource implications.”[17]

“A greenhouse experiment demonstrated that drought does reduce both pollen and nectar production by I. aggregata flowers.”[18]

Drought stress reduces the amounts of flowers available as well as the amount of nectar available in flowers produced.[19]

Such nutritional and heat stress results in lower production of offspring and overall reproduction.[20] With three-quarters of the United States gripped in the worst drought in decades and California in the worst year since 1977, the effect of pollution on drought can no longer be ignored. Our focus needs to redirect towards carbon sequestration through soil science, replanting our landscapes with drought tolerant plants, and keeping our trees alive.  After all, a growing body of evidence is emerging that trees not only sequester carbon and reduce pollution, but they can also cause rain.[21]

This year, beekeepers in Southern California are reporting reduced growth of colonies and reduced nectar flow. For the first time since starting bee rescues and beekeeping, our relocations and colony populations are low. The forecast from our firefighters is that moisture levels are two months prematurely reduced. This summer dearth (limited resources for pollinators) and subsequent fire season looks bleak. When you become a beekeeper, people begin to treat you like a hero. We become stewards of a cornerstone species we can closely observe for monitoring climate change. We become intuitively connected to changes in floral resources. It then becomes our responsibility to represent as stewards, not only honeybees, but all pollinators, and to be the hero. Beekeeping then morphs into a vehicle for advocating environmental health. Whether or not you too are a beekeeper, plant trees and plants either at home, at a local community garden, or with a local organization. Provide food sources, habitat, and water for our pollinators. You will receive a bounty of beauty in return.

Sunscreen Blend

This recipe yields 12-oz./340 g of sunscreen. You will need suitable containers such as 12 x 1-oz. jars.

---

Ingredients:

4-oz./120 mL calendula, organically grown (Calendula officinalis), organic sunflower (Helianthus annuus) oil, organic and sustainable red palm (Cyrtostachys renda) oil

4-oz./120 mL certified organic shea butter (Butyrospermum parkii)

2-oz./60 mL certified organic argan (Argania spinosa) oil

2-oz./60 mL certified organic jojoba (Simmondsia chinensis)

2-oz./60 mL certified organic coconut (Cocos nucifera) oil

10-oz./285 g certified organic beeswax (Cera alba)

2 tsp. certified organic rosemary antioxidant extract Rosemary (Salvia rosmarinus) and olive oil (Olea europaea)

6-oz./170 g non-nano uncoated zinc oxide

---

Essential Oils (Optional):

40 drops of lavender (Lavandula angustifolia)

To Make: Gently melt all of the oils and beeswax using the bain marie method. Once blended, take off of the stove top. Add the zinc oxide and essential oils. Stir. Cool for one hour in a large bowl and place in the refrigerator. Once cooled, put the mixture into a blender or food processor to whip. Once finished, scoop into containers.

To Use: Apply as needed when outdoors.

Cautions: For adult use only.

Amanda’s Tips: If you would like to make tinted sunscreen, blend organic raw cocoa powder in while melting. This may take a few attempts to get the right shade for your skin. The ratio of oils to zinc is 24-oz./710 mL oils to 6-oz./170g zinc. Please ensure you buy non-nano and uncoated zinc. With natural sunscreen, it is best to apply one hour before being out in the sun and reapply upon arrival. Be sure to consistently reapply when you are out in the sun and after getting wet.

---

References:

Cseke, Leland J., et al. “The Biology of Essential Oils in the Pollination of Flowers.” Natural Product Communications, vol. 2, no. 12, 2007, pp. 1317–1336., doi:10.1177/1934578x0700201225. Accessed 25 June 2021 from:  https://journals.sagepub.com/doi/pdf/10.1177/1934578X0700201225

Figueiredo, A. Cristina, et al. “Factors Affecting Secondary Metabolite Production in Plants: Volatile Components and Essential Oils.” Flavour and Fragrance Journal, vol. 23, no. 4, 2008, pp. 213–226., doi:10.1002/ffj.1875.Accessed from: https://iks.ukzn.ac.za/sites/default/files/Factors%20affecting%20secondary%20metabolite%20production%20in.pdf

Figueiredo, A. Cristina, et al. “Factors Affecting Secondary Metabolite Production in Plants: Volatile Components and Essential Oils.” Flavour and Fragrance Journal, vol. 23, no. 4, 2008, pp. 213–226., doi:10.1002/ffj.1875. Accessed from: https://iks.ukzn.ac.za/sites/default/files/Factors%20affecting%20secondary%20metabolite%20production%20in.pdf

Fact Sheet: Ozone and Ozone Standards - The Basics. www.epa.gov/sites/production/files/2016-04/documents/20151001basicsfs.pdf. Accessed from: https://www.epa.gov/sites/production/files/2016-04/documents/20151001basicsfs.pdf

“Watching Our Ozone Weather.” NASA, NASA, earthobservatory.nasa.gov/features/OzoneWx/OzoneWx3.php. Accessed from: https://earthobservatory.nasa.gov/features/OzoneWx/OzoneWx3.php

“Ozone Concentrations.” Ozone Concentrations | Vital Signs, www.vitalsigns.mtc.ca.gov/ozone-concentrations. Accessed from: https://www.vitalsigns.mtc.ca.gov/ozone-concentrations

 Solis, Nathan. “Amid Wildfires, Los Angeles Registers Highest Ozone Pollution in 26 Years.” Courthouse News Service, 11 Sept. 2020. Accessed from: www.courthousenews.com/amid-wildfires-los-angeles-registers-highest-ozone-pollution-in-26-years/ 

North Central Texas Council of Governments Air Quality. Accessed from: https://www.nctcog.org/nctcg/media/Transportation/DocsMaps/Quality/Air/AQHandbook2018.pdf

“Dr. Duke's Phytochemical and Ethnobotanical Databases Facilitate In-Depth Plant, Chemical, Bioactivity, and Ethnobotany Searches Using Scientific or Common Names. Search Results Can Be Downloaded in PDF or Spreadsheet Form. Of Interest to Pharmaceutical, Nutritional, and Biomedical Research, as Well Alternative Therapies and Herbal Products.” Dr. Duke's Phytochemical and Ethnobotanical Databases at NAL, phytochem.nal.usda.gov/phytochem/search. Accessed from: https://phytochem.nal.usda.gov/phytochem/chemicals/report/12607.pdf

Penn State. "Bees' ability to forage decreases as air pollution increases." ScienceDaily. ScienceDaily, 6 July 2016. Accessed from: https://www.sciencedaily.com/releases/2016/07/160706131924.htm     

“Dr. Duke's Phytochemical and Ethnobotanical Databases Facilitate In-Depth Plant, Chemical, Bioactivity, and Ethnobotany Searches Using Scientific or Common Names. Search Results Can Be Downloaded in PDF or Spreadsheet Form. Of Interest to Pharmaceutical, Nutritional, and Biomedical Research, as Well Alternative Therapies and Herbal Products.” Dr. Duke's Phytochemical and Ethnobotanical Databases at NAL, phytochem.nal.usda.gov/phytochem/search. Accessed from:      https://phytochem.nal.usda.gov/phytochem/chemicals/report/3626.pdf

Penn State. "Bees' ability to forage decreases as air pollution increases." ScienceDaily. ScienceDaily, 6 July 2016. Accessed from: https://www.sciencedaily.com/releases/2016/07/160706131924.htm

Interest, Post author By Compound, et al. “The Chemical Compounds Behind the Smell of Flowers.” Compound Interest, 3 May 2015. Accessed from: www.compoundchem.com/2015/02/12/flowers/

Penn State. "Bees' ability to forage decreases as air pollution increases." ScienceDaily. ScienceDaily, 6 July 2016. Accessed from: https://www.sciencedaily.com/releases/2016/07/160706131924.htm

Farré-Armengol, G., Peñuelas, J., Li, T., Yli-Pirilä, P., Filella, I., Llusia, J. and Blande, J.D. (2016), Ozone degrades floral scent and reduces pollinator attraction to flowers. New Phytol, 209: 152-160. Accessed from: https://doi.org/10.1111/nph.13620

Sirk, Emerson. “Air Quality Implications for Pollinator Species.” NASA.gov, 2018. Accessed from:  https://airquality.gsfc.nasa.gov/sites/default/files/airquality/Sirk_AQ_honeybees.pdf

University of Maryland. "Rising air pollution worsens drought, flooding, new study finds." ScienceDaily. ScienceDaily, 14 November 2011. Accessed from: https://www.sciencedaily.com/releases/2011/11/111113141304.htm

Waser NM, Price MV. Drought, pollen and nectar availability, and pollination success. Ecology. 2016 Jun;97(6):1400-9. doi: 10.1890/15-1423.1. PMID: 27459771. Accessed from: https://pubmed.ncbi.nlm.nih.gov/27459771/

Phillips, Benjamin B., et al. “Drought Reduces Floral Resources for Pollinators.” Global Change Biology, vol. 24, no. 7, 2018, pp. 3226–3235., doi:10.1111/gcb.14130. Accessed from: https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.14130

Vanderplanck, Maryse, et al. “Ensuring Access to High-Quality Resources Reduces the Impacts of Heat Stress on Bees.” Scientific Reports, vol. 9, no. 1, 2019, doi:10.1038/s41598-019-49025-z. Accessed from: https://www.nature.com/articles/s41598-019-49025-z

Rainforest-initiated wet season onset Jonathon S. Wright, Rong Fu, John R. Worden, Sudip Chakraborty, Nicholas E. Clinton, Camille Risi, Ying Sun, Lei Yin Proceedings of the National Academy of Sciences Aug 2017, 114 (32) 8481-8486; DOI: 10.1073/pnas.1621516114. Accessed from: https://www.pnas.org/content/114/32/8481

Jose D. Fuentes, Marcelo Chamecki, T’ai Roulston, Bicheng Chen, Kenneth R. Pratt, “Air pollutants degrade floral scents and increase insect foraging times,” Atmospheric Environment, Volume 141, 2016, Pages 361-374, ISSN 1352-2310. Accessed from: https://doi.org/10.1016/j.atmosenv.2016.07.002

---

About Amanda Plunkett:

 After years of suffering with an environmental illness, Amanda turned to holistic medicine. She began her aromatic education by obtaining her Advanced Aromatherapy and Internal Usage Certifications under the mentorship of Jade Shutes in 2015 with over 500 hours of training. She now serves the community as a NAHA Certified Clinical Aromatherapist®. In 2016, she launched Bee Rooted, a company dedicated to advocating for healthy environments and rescuing nuisance honeybees. Since then, she has also successfully completed a horticulture class and gained an Organic Lawn Care Accredited Professional Certification through the Organic Landscape Association and the Northeast Organic Farming Association. 

As an Environmental Illness survivor, she feels she has a special relationship with bees as they too are sensitive to miniscule environmental changes. She uses her experience to spread awareness for healthier environments, offering consultations and presentations around the country on holistic personal care, organic landscaping, and developing habitat for pollinators.  Amanda is the Southern California regional director for NAHA. To learn more about Amanda, visit her website at: www.beerooted.com.