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The Chemicals of Summer: A Four-Part Evernorth Summer Series
- Victoria
- Jun 11
- 6 min read
Summer is a season of sunshine, beautiful gardens, and time spent outdoors.
It is also a season filled with synthetic products and materials that have become staples of what most people associate with summertime fun. Many of these products were created with good intentions: to protect us, preserve our landscapes, improve convenience, or solve everyday problems. Yet many of these materials and products can affect both our bodies and the environments we inhabit in detrimental ways.
Over the next four weeks, we'll explore some of the most common chemical exposures associated with summer time and introduce organically compatible alternatives that allow us to enjoy the season while living purely organic.
Week I: Skin Deep: Sunscreen & Insect Repellent
Week II: Around Our Homes & Gardens: Lawn Fertilizers, Herbicides, Garden Pesticides and Fungicides, Mosquito Yard Treatments
Week III: Where We Gather: Pool chemicals, artificial turf, rubber mulch, playground and recreation surfaces
Week IV: Beyond Our Backyard: Agricultural spraying, roadside vegetation management, parks and public spaces, summer air quality
Week I: Skin Deep: Sunscreen & Insect Repellent
Summertime calls for sunscreen and the overpowering scent of insect repellent. For most, these staples are thought of as purely protective measures without realizing the potential negative effects they have on both our bodies and the environment alike.
Our skin is our body’s largest organ and our first line of defense against the outside world. It is also far more absorptive than it was once assumed to be. And thus, the products we apply to it deserve meaningful consideration.
Sun Protection: A Closer Look at What We’re Choosing
Effective sun protection is an integral part of a healthy skincare routine, and the purpose of this piece is to illuminate which protection items on the market are most ideal for ourselves and our planet.
Zinc Oxide and titanium dioxide are the only two sunscreen active ingredients recognized by the U.S. Food and Drug Administration as having sufficient evidence to be classified as generally safe and effective, a designation known as GRASE.
Twelve other commonly used chemical filters, including avobenzone, oxybenzone, octocrylene, octinoxate, octisalate, and homosalate are common sunscreen ingredients on the market today, despite not having a category I classification (GRASE).
In 2019 and again in 2020, FDA researchers conducted clinical trials to measure the effects of standard sunscreen products. Volunteers applied commercially available sunscreens, sprays, lotions, and creams, under maximal use conditions, and researchers measured what showed up in their blood. Plasma concentrations of avobenzone, oxybenzone, octocrylene, and ecamsule all exceeded the FDA’s own safety threshold of 0.5 nanograms per milliliter on the very first day of use, in every participant tested, with Oxybenzone reaching that threshold within two hours of a single application.
In other words, these chemicals are not simply sitting on the surface of the skin, they are entering the blood stream. This data has prompted concern among researchers studying endocrine function, particularly given that several of these are classified as potential hormone disruptors, compounds capable of interfering with the body’s own signaling systems at vanishingly small concentrations.
Oxybenzone in particular has drawn sustained scientific attention for its ecotoxicity against coral reefs. When this synthetic compound reaches rivers and oceans, corals and sea anemones absorb the oxybenzone and convert it into a compound that becomes toxic when exposed to sunlight, and that toxic compound gets trapped inside the coral itself.
In one study, researchers compared two nearby locations, one being a heavily visited tourist spot with a lot of sunscreen runoff, and a less trafficked bay nearby. Over five years, the tourist location had no new baby coral settle, no young coral survive, and no damaged coral heal. Whereas the less disturbed bay, facing the same general environmental pressures, had a thriving coral community.
This implies that a chemical applied to protect human skin from the sun may be disabling a reef’s own defenses against the sun.
Considering there are safer, more natural, and less toxic options readily available to the public, why have certain compounds not been restricted or banned from production?
In some places, they have. A growing number of marine protected areas, including Hawaii and the U.S. Virgin Islands have moved to restrict oxybenzone and octinoxate specifically, raising the question of whether the rest of the country will follow.
What This Means for Your Sunscreen Picks
You can make choices that protect yourself, your family, as well as the environment by simply choosing mineral sunscreens in the form of a cream, lotion, or stick, formulated with zinc oxide or titanium dioxide as their active ingredient.
These are the two safe formulations that sit on top of the skin and reflect ultraviolet light.
While the thicker white formula may take longer to apply, the trade-off is worth it against the alternatives
The Other Half of the Routine: Insect Repellent
No one wants an assortment of bug bites or tick encounters, so the majority of us suck it up and spray away before hiking a trail during the warm months.
DEET has been the most widely used insect repellent in the world for nearly seventy years, and the EPA maintains that it does not present a health concern when used as directed.
Independent research shares another perspective. A Swedish occupational study linked long-term DEET use to an increased risk of testicular cancer, a result health authorities call inconclusive rather than disproven.
Beyond human wellness, DEET is also one of the most frequently detected contaminants in surface water worldwide, persisting through conventional wastewater treatment rather than breaking down, and it is, by its own chemistry, a solvent capable of degrading plastics and synthetic fabrics on contact.
For those looking to distance themselves from the controversy of DEET, and opt for more natural, less potentially harmful products, two genuinely different paths are available, one synthetic and one fully botanical.
A known safer synthetic alternative is picaridin. It is still a manufactured compound, so it is not an organic choice, but long-term studies have found no cancer signal and no evidence of hormone disruption, and it breaks down in soil rather than lingering in waterways.
A fully natural, genuinely organic option is organic clove oil, alongside organic cinnamon oil and organic geraniol. A 2023 study in Scientific Reports tested twenty essential oils against mosquitoes and blacklegged ticks using the same contact-repellency methods used on DEET itself, and clove and cinnamon oil were the only two that performed well against both, with geraniol close behind, especially against ticks, which matters for life in tick country.
For the deep dive into sun screen and insect repellents, read the full article where we go deeper into the research.
Reading the Label
Today’s consumers have more choices than ever before. Reading ingredient labels, understanding why each ingredient is included, and exploring organically compatible alternatives are small decisions that can make a big impact on both human wellness and that of the environment.
So, when your in the summer care aisle next, remember that mineral sunscreen, a picaridin-based repellent, or a clove or geraniol-based repellent are the versions that offers safer, more natural summer protection.
Next week, we’ll step beyond the products we place on our skin and into the spaces surrounding our homes, as we explore lawn treatments, garden chemicals, and the products used to beautify our outdoor landscapes.
Sources:
1. U.S. Food and Drug Administration. Questions and Answers: FDA Posts Deemed Final Order and Proposed Order for Over-the-Counter Sunscreen. FDA.gov.
2. Matta, M.K., Zusterzeel, R., Pilli, N.R., et al. “Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.” JAMA, 321(21), 2082–2091, 2019.
3. Matta, M.K., Florian, J., Zusterzeel, R., et al. “Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.” JAMA, 323(3), 256–267, 2020.
4. Downs, C.A., Kramarsky-Winter, E., Segal, R., et al. “Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands.” Archives of Environmental Contamination and Toxicology, 70(2), 265–288, 2016.
5. U.S. Environmental Protection Agency. Reregistration Eligibility Decision (RED) for DEET. EPA, Office of Pesticide Programs.
6. Hardell, L., Bavel, B., Lindström, G., et al. “Case-Control Study on Risk Factors for Testicular Cancer.” International Journal of Andrology, 1998.
7. Environmental Impact of DEET: Monitoring in Aquatic Ecosystems and Ecotoxicity Assessment. ACS ES&T Water, 2025.
8. U.S. Environmental Protection Agency. Pesticide Fact Sheet for Picaridin (PC-070705), May 2005.
9. Luker, H.A., Salas, K.R., Esmaeili, D., Holguin, F.O., Bendzus-Mendoza, H., Hansen, I.A. “Repellent Efficacy of 20 Essential Oils on Aedes aegypti Mosquitoes and Ixodes scapularis Ticks in Contact-Repellency Assays.” Scientific Reports, 13, 1705, 2023.
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