compounds

Aluminum And Deodorants | Earth Wise

October 2, 2020 By EarthWise Leave a Comment

Aluminum is the third most common element in the earth’s crust. That element and its compounds are contained in numerous foods and products intended for consumers. Aluminum can occur naturally in certain foods and it can be a part of food additives. Apart from that, it is also possible for aluminum to transfer to food from packaging and tableware. We also can take in aluminum from cosmetic products like whitening toothpaste, lipsticks, particles in sunscreens, and in the form of aluminum chlorohydrate in antiperspirants.

The concern about aluminum intake is related to its effects on the nervous system, on the mental and motor development of children, and upon possible negative effects on the kidneys and bones. When aluminum is ingested via food, its toxicity is low and for healthy people, the kidneys do a good job of excreting it. However, people with chronic kidney disease may not be able to get rid of aluminum as readily and it can accumulate in the body.

Six years ago, a study looked at the amount of aluminum absorbed through the skin from the use of antiperspirants, but the data at that time was considered to be unreliable and a need for further research was identified.

Recently, the results of two new studies have been published by a German research institute that quantifies the absorption of aluminum salts through the skin. The results were that significantly less aluminum is absorbed through the skin than previously calculated and that a significant absorption of aluminum from antiperspirants is unlikely.

The total burden of aluminum from all sources can be high among some population groups, but it appears that use of aluminum-containing antiperspirants is not an important contribution to that burden.

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Aluminium in antiperspirants: Low contribution to the total intake of aluminium in humans

Photo courtesy of NutritionFacts.org.

Earth Wise is a production of WAMC Northeast Public Radio.

PFAS In The Food Chain | Earth Wise

July 8, 2020 By EarthWise Leave a Comment

Per- and polyfluoroalkyl substances (PFAS) are a family of human-made chemicals that have been manufactured and used in a variety of industries around the globe. PFOA and PFOS have been the most extensively produced and the most extensively studied of these chemicals.

Exposure to PFAS has been linked to a host of adverse health effects, including thyroid hormone disruption and cancer.

PFAS compounds can be found in such things as non-stick cookware, stain-resistant carpets, water-repellent outdoor gear, and food packaging, like fast food wrappers and microwave popcorn bags.

According to a new study, researchers from North Carolina State University have found PFAS substances in every step of the Yadkin-Pee Dee River food chain, even though the river doesn’t have a known industrial input of these compounds.

The team collected water, sediment, algae, plant, insect, fish, crayfish, and mollusk samples at five sites along the river and analyzed them for 14 different PFAS compounds. Nearly every sample tested contained PFAS compounds. Biofilm contained the largest concentrations of 10 of the 14 PFAS compounds measured. Insects, which primarily eat biofilm, had the greatest accumulation of PFAS compounds of all the living taxa the researchers sampled.

When PFAS compounds are present at every step of the food chain, the compounds accumulate at each step leading to greater concentrations in animals that sit higher on the food chain – including humans. This is known as biomagnification.

Studies like this that reveal how prevalent PFAS can be within ecosystems without an industrial input highlight the need for further research into how these compounds affect the environment and human health.

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PFAS present throughout the Yadkin-Pee Dee river food chain

Photo, posted May 24, 2011, courtesy of the U.S. Fish and Wildlife Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Safer Disposal Of Printed Circuit Boards | Earth Wise

March 4, 2020 By EarthWise Leave a Comment

Printed circuit boards are key elements of modern electronic devices that support and connect all of their electronic components. On average, they are composed of 30% metallic and 70% nonmetallic substances.

Once the circuit boards have served their purpose, they are often burned or buried in landfills, and can pollute the air, soil, and water. The biggest problem is that they have brominated flame retardants added to them in order to keep them from catching fire. Compounds in brominated flame retardants have been linked to endocrine disorders and fetal tissue damage.

Many circuit boards are recycled to recover valuable materials – generally the metals they contain. But recycling has its own problems. Metallic components can be recovered from crushed circuit boards by magnetic and high-voltage electrostatic separations. When the metals are removed, what remains are resins, reinforcing materials, brominated flame retardants, and other additives, which are of little value and present various dangers.

Researchers at Sun Yat-sen University in China have developed a ball-milling method to break down these potentially harmful compounds, enabling safe disposal. A ball mill is a rotating machine that uses small agate balls to grind up materials. The researchers also added iron powder, which helps remove bromine from organic compounds by breaking the carbon-bromine bonds in the flame retardants. The result was particles with half of their bromine content removed as well as decomposition of phenolic resin compounds.

The ever-increasing proliferation of device technology had led to a new set of pollution and waste challenges facing society. Research on ways to reduce the impact of high-tech garbage is an important need for society.

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