crust

Americans And Lead Exposure | Earth Wise

April 4, 2022 By EarthWise Leave a Comment

Long-term exposure to lead can cause serious health problems, especially in children. Children are particularly vulnerable because their early years are characterized by rapid growth and brain development.

Lead is a powerful neurotoxin that can cause damage even at low levels of exposure. Lead poisoning can be acute, and can cause all sorts of health issues, including stomach pain, brain damage, and even death. Because lead accumulates in the body over time, lead poisoning can develop slowly. Exposure to lead can also contribute to a lower IQ and behavioral problems that can last a lifetime.

Lead is a naturally occurring element found in small amounts in earth’s crust. But as a result of human activities, lead can be found in all parts of the environment, including the air, soil, and water.

According to a new study recently published in the journal Proceedings of the National Academy of Sciences, approximately half of U.S. adults alive today were exposed to harmful levels of lead as children from the burning of leaded gasoline. The research team estimates that lead contamination has lowered those Americans’ IQ scores by more than two points on average.

In the study, the researchers used data on childhood blood-lead levels, leaded gasoline use, and population to gauge the lifetime exposure of every American adult in 2015. They found that more than 170 million Americans had exposure to concerning levels of lead as children. Those who grew up in the 60s and 70s, when the burning of leaded gasoline was at its peak, had the greatest exposure, losing up to six IQ points on average.

The legacy of lead exposure remains a persistent problem.

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Half of Americans Exposed to Harmful Levels of Lead as Children

Lead Exposure Remains A Persistent Problem

Photo, posted February 13, 2010, courtesy of Steve Snodgrass via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electronic Waste On The Decline | Earth Wise

January 6, 2021 By EarthWise Leave a Comment

A new study published in the Journal of Industrial Ecology has found that the total mass of electronic waste generated by Americans has been declining since 2015. Given that electronic devices are playing an ever-growing role in our lives, this finding seems rather surprising. It also seems like pretty good news, but the underlying facts should dampen our level of enthusiasm.

The main reason for the decline is the disappearance of large, bulky cathode-ray tube televisions and computer monitors. Since about 10 years ago, CRT displays have been on the decline in the waste stream, thereby leading to an overall decline in total e-waste mass.

Many state regulations with respect to e-waste recycling have targets based on product mass. The regulations were typically designed to keep electronics with high levels of lead and mercury out of landfills.

At present, the more pertinent concern is how to recover valuable elements like cobalt (from lithium-ion batteries) and indium (from flat-panel displays). These elements are not so environmentally toxic, but rather are relatively scarce in the earth’s crust.

The main conclusion to be drawn from the declining mass of electronic waste is not that we are necessarily winning the battle against generating it but rather that e-waste is changing and regulations concerning it need to be rethought. Focusing regulations on capturing critical elements not only would have significant economic benefits but also would be important in addressing geopolitical uncertainties that potentially could threaten what could be termed the mineral security of the U.S.

E-waste recycling is regulated at the state level and only half the states have e-waste recycling laws. It may be time for more uniform policies across the country.

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Electronic Waste on the Decline, New Study Finds

Photo, posted January 22, 2013, courtesy of Thorsten Hartmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Caribbean Coral Reefs Under Siege | Earth Wise

January 4, 2021 By EarthWise Leave a Comment

Coral reefs around the world have been suffering from warming seas and increasing acidification, both a result of human activity. In the Caribbean, a new threat has emerged in the form of invasive algae.

New research published in Scientific Reports explains how an aggressive, crust-like alga is overgrowing shallow reefs and taking the place of coral that was damaged by powerful storms that exposed areas of the undersea rock where corals grew.

Researchers from Oxford University, the Carnegie Institution, and California State University Northridge have been studying these peyssonnelid algal crusts, or PACs, for several years in the U.S. Virgin Islands. The PAC has been out-competing coral larvae for surface space and then growing over the existing reef architecture, greatly damaging delicate reef ecosystems.

New corals actually prefer to settle on crusty surfaces created by a different type of algae called crustose algae, or CCA. CCA acts as guideposts for coral larvae by producing biochemical signals as part of a microbial community that entice baby coral to affix itself.

In contrast, the destructive PAC algae exclude coral settlement. The researchers determined that the microbial community associated with PAC algae is deployed to deter grazing from fish and other marine creatures. Unfortunately, it also deters coral.

Fragile coral ecosystems are already under assault by environmental pollution and global warming. Now, in the aftermath of powerful hurricanes like Irma and Maria, algal crusts are taking over reef communities and posing an existential threat to Caribbean corals.

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An unusual microbiome characterises a spatially-aggressive crustose alga rapidly overgrowing shallow Caribbean reefs

Photo, posted January 11, 2015, courtesy of Falco Ermert via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

China And Rare Earth Mining

September 4, 2019 By EarthWise Leave a Comment

Rare earth elements are a crucial part of much of modern technology. Everything from computers to X-ray machines and aircraft engines needs one or more rare earth elements for magnets, lenses, and other functions. The world’s tech giants such as Apple, Huawei, and Tesla depend on suppliers of rare earths.

Rare earth elements are not actually rare, but they are very expensive to extract in ways that are not extremely harmful to the environment. China has been a major source of these elements since its rare earth mining industry took off in the 1990s. The removal of rare earths from the earth’s crust, using a mix of water and chemicals, has caused extensive water and soil pollution.

Today, concrete leaching ponds and plastic-lined wastewater pools dot the hills of Southeast China. Large wastewater ponds sit uncovered and open to the elements in many places. Landslides or barrier failures can spill contaminated contents into waterways or groundwater.

Local and federal officials in China have started to shut down illegal and small-scale rare earth mining operations and have embarked on a cleanup of polluted sites. The rare earth mining cleanup operation is part of wider efforts across China to address severe problems of water, air and soil pollution.

China’s Ministry of Industry and Information Technology estimated that the cleanup bill for southern Jiangxi Province could amount to more than $5 billion. Many environmental experts and local officials say that the cost of the cleanup should not be shouldered by the Chinese government alone, but also by the rare earth industry and the global companies and consumers that benefit from rare earth technology. As rare earth mining efforts start up elsewhere around the world, it is important not to repeat the mistakes made in China.

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China Wrestles with the Toxic Aftermath of Rare Earth Mining

Photo, posted April 21, 2019, courtesy of John Beans via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.