Sunscreen's Dark Side: Is It Polluting Our Environment?

Sunscreen is an essential product for protecting human skin against sun damage. However, its impact on the environment has become a growing concern. Sunscreen use has increased in recent years, and with it, the discharge of sunscreen products into aquatic environments, causing pollution that affects marine life and ecosystems. Certain chemicals commonly found in sunscreen formulas, such as oxybenzone, octinoxate, and avobenzone, have been identified as harmful to coral reefs, fish, and other aquatic species. These chemicals can cause coral bleaching, impair the growth of algae, and affect the metabolism, physiology, and behaviour of marine fauna. While mineral-based sunscreens that use zinc oxide or titanium dioxide as UV blockers are considered less harmful, the effects of chemical UV filters on reef ecosystems are still being actively researched.

Sunscreen chemicals can contaminate water systems and cause coral bleaching

Sunscreen use has increased in recent years, as these products minimize the damaging effects of solar radiation. However, certain chemicals commonly found in many formulas have been shown to contaminate water systems and harm marine life, including coral reefs.

It is estimated that approximately 14,000 tons of sunscreen enter waterways globally every year from sunscreen applications and wastewater runoff. In shallow areas frequented by swimmers, significant amounts of sunscreen can accumulate in the water. Sunscreen ingredients can be introduced into the environment when swimmers enter the ocean, rivers, and lakes, and the sunscreen they have applied to their skin washes off into the water.

Both organic and inorganic UV filters have been detected in marine ecosystems through water sampling from various places around the globe. The concentration of pollutants varies depending on several factors, such as the area, date, and time of sampling, and whether swimmers are present. The increase in tourism in coastal areas has been correlated with higher concentrations of UV agents in the waters of these regions.

Coral reefs are among the most biologically productive and diverse ecosystems globally, providing food protein for half a billion people. However, they face serious threats from various sources, including climate change, unsustainable fishing, land-based pollution, and coastal development. Chemicals found in sunscreen and other personal health products have been identified as a threat to the health of coral reefs. Certain active ingredients in sunscreen, such as oxybenzone, octinoxate, benzophenone, and camphor derivatives, can induce coral bleaching, damage DNA, deform young corals, and even lead to coral death.

Studies have found that even at extremely low concentrations, sunscreen products can cause abrupt and complete bleaching of hard corals. The symbiotic algae that live in healthy coral tissue, known as zooxanthellae, provide nutrients to corals through photosynthesis and contribute to their vibrant colors. When corals lose their zooxanthellae, they also lose their color, leaving their protective skeletons exposed, which eventually leads to their death. Additionally, sunscreen chemicals can stimulate dormant viral infections in zooxanthellae, causing an explosion of viruses that can spread to nearby coral communities.

Oxybenzone is one of the most environmentally toxic active ingredients in sunscreen

Oxybenzone is a common ingredient in sunscreen, especially in chemical sunscreens, which contain chemicals that absorb the sun's ultraviolet rays. Oxybenzone has received a lot of negative attention due to concerns about its potential impact on human health and the environment.

Oxybenzone has been identified as a hormone disruptor, also known as an endocrine disruptor. It has the ability to cross cell membranes and interfere with the body's natural hormone production. Studies have shown that oxybenzone can be absorbed through the skin, leading to significant systemic exposure. This has raised concerns about its potential health effects, including an increased risk of breast cancer and endometriosis. The National Toxicology Program also found evidence of carcinogenicity in rats, with increased thyroid tumours and enlargement of the uterus in female rats exposed to high levels of oxybenzone.

In addition to its potential health risks, oxybenzone is also considered environmentally toxic. It is classified as a hazardous irritant for eye contact and slightly hazardous for direct skin contact. Oxybenzone penetrates the skin and helps other chemicals penetrate as well. According to the Center for Disease Control (CDC), 97% of Americans have this chemical circulating in their bodies. It is also a common contaminant in wastewater, as it is used in many personal care products beyond sunscreen, such as plastic, hairspray, nail polish, and toothpaste.

The environmental impact of oxybenzone is particularly concerning for coral reefs. Oxybenzone is one of the specific chemical UV filters that have been found to harm aquatic life and corals. It is considered a contributing factor to coral bleaching, which can eventually lead to coral death. This is a significant issue as coral reefs are already facing serious threats from climate change, unsustainable fishing practices, land-based pollution, and other human activities.

While there is ongoing research into the environmental impacts of oxybenzone and other sunscreen ingredients, some places, like Hawaii, have already taken action by banning sunscreens containing oxybenzone and other harmful chemicals. To protect both human health and the environment, it is recommended to choose sunscreens without oxybenzone and similar toxins. Mineral sunscreens, which do not contain chemical UV filters, are generally considered a safer option.

Other cosmetic products like moisturisers, shampoos and makeup may also contain UV filters

Sunscreen use has increased in recent years, as sunscreen products minimize the damaging effects of solar radiation. Active ingredients called ultraviolet (UV) filters or UV agents are responsible for defending skin tissue. However, certain UV filters found in chemical sunscreens can contaminate water systems and harm aquatic life, including corals.

Other Cosmetic Products Containing UV Filters

UV filters are widely used in everyday cosmetic products such as moisturisers, shampoos, and makeup. A market survey of cosmetic products containing UV filters found that 49.1% of the makeup products studied and 74.3% of perfumes contained UV filters. The presence of UV filters in these products can contribute to marine pollution, as these ingredients can be washed off into water systems.

A comparative study on UV filters in everyday cosmetic products found these filters as contaminants in a variety of biological fluids and environments, including vegetable crops and surface water. The study also focused on the potential health impacts of exposure to UV filters through cosmetic products, as these filters have been detected in human urine and indoor dust.

The pursuit of new UV filters through research is crucial to advancing sunscreen and cosmetic technology and ensuring the availability of effective and safe options for sun protection. For example, a new UVA1 filter, MCE, was approved by the SCCS for use in sunscreen products up to 3% in 2020. This filter prolongs the range of absorption up to 400 nm and diminishes the adverse effects of UVA1 radiation on the skin.

Mineral sunscreens, which use zinc oxide or titanium dioxide, are considered reef-friendly

Sunscreen use has increased in recent years, as sunscreen products minimize the damaging effects of solar radiation. However, certain active ingredients in sunscreen can cause coral bleaching and even coral death. Oxybenzone, octinoxate, and avobenzone are some of the chemicals found in sunscreen that can harm coral reefs.

Zinc oxide and titanium dioxide are effective UV-blocking ingredients, but their particle size can impact their safety for marine life. When used at the nanoparticle level, these minerals can be toxic to marine life and potentially humans. Therefore, it is recommended to use micro-sized or non-nano zinc oxide and titanium dioxide, which are less likely to leach into the marine environment and cause harm.

Some examples of reef-friendly mineral sunscreens include:

• REN Clean Screen Mineral SPF 30 Mattifying Face Sunscreen (active: uncoated 22% zinc oxide)
• Amavara Mineral Sunscreens (active: zinc oxide 19% - 22.25%)
• TropicSport Mineral Sunscreens (active: zinc oxide 8.6%, titanium dioxide 4.55%)

Sunscreen pollution can have an impact on the whole ecosystem, including fish and mammals

Sunscreen use has increased in recent years, as sunscreen products minimize the damaging effects of solar radiation. However, sunscreen pollution can have a significant impact on the entire ecosystem, including corals, fish, and mammals.

The sunscreen we apply to our skin may enter waterways when we swim or shower, eventually making its way into wastewater systems. Wastewater treatment plants often fail to remove these pollutants efficiently, leading to their transfer into marine ecosystems and even tap water. Both organic and inorganic UV filters have been detected in marine ecosystems through water sampling from various locations worldwide. These filters are also present in other cosmetic products like moisturizers, shampoos, and makeup, contributing to the issue.

The effects of sunscreen pollution on the ecosystem are far-reaching. For instance, certain active ingredients in sunscreens can cause coral bleaching, which may lead to coral death. Coral reefs, being sensitive to environmental changes, face threats from climate change, unsustainable fishing, land-based pollution, and other factors. Sunscreen pollution exacerbates these issues, impairing the growth of green algae, an essential part of the food web. The consequences can be observed throughout the food chain, even impacting vulnerable species like the Hawaiian green sea turtle.

Additionally, sunscreen chemicals can accumulate in the tissues of fish and dolphins, leading to decreased fertility and reproduction, and the development of female characteristics in male fish. Chemicals like oxybenzone, octinoxate, and avobenzone, commonly found in sunscreens, have been detected in high concentrations around coral reef sites.

To address this issue, some states, such as Hawaii, have banned sunscreens containing these harmful chemicals, encouraging the use of coral reef-safe alternatives. It is essential to opt for sunscreens without toxins like oxybenzone and similar compounds to protect both our health and the environment.

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