Human Health on EARTH Magazine

Rising carbon dioxide may raise risk of nutrient deficiencies in humans

Fri, 21 Dec 2018 10:54:40 -0500

In a new study, researchers found that levels of zinc, iron and protein in some grains and legumes will drop as atmospheric carbon dioxide concentrations rise. Credit: public domain.

Plants absorb carbon dioxide to fuel their growth. As humans increase the amount of the greenhouse gas in the atmosphere, more will be available to vegetation around the world. But according to a new study, too much carbon dioxide might eventually lead to plants that are deficient in key nutrients for humans, which could be especially detrimental in the developing world.

The geology of kidney stones revealed

Fri, 21 Dec 2018 10:31:39 -0500

Kidney stones are an excruciatingly painful problem for 10 percent of the world’s population. In a new study applying geobiological methods to the study of human kidney stones, researchers have shed light on how the stones form, and revealed that they partially and repeatedly dissolve inside the kidney — which could help in developing new protocols to treat the pervasive affliction.

Mercury on the roof of the world

Tue, 16 Oct 2018 10:31:23 -0400

Mercury, the only metal that is liquid at room temperature, is extremely toxic to humans and has detrimental effects if excreted into the environment. Credit: Hi-Res Images of Chemical Elements (CC by 3.0)

Traditional Tibetan Medicines (TTM) are dispensed in pill form by pharmacists who mix minerals and herbs together in centuries-old recipes. But some of the ingredients may be doing more harm than good. Previous studies have found that mercury and methylmercury, both highly toxic to humans, are sometimes intentionally used in the medications. In a new study, published in Environmental Science & Technology, researchers analyzed total mercury and methylmercury concentrations in seven common TTM remedies and found concentrations as high as 12,000 micrograms per gram and averaging 5,600 micrograms per gram. They found that daily mercury intake by Tibetans who practice traditional medicine was as much as 3,000 times higher than exposure rates in the general populations in Japan, Norway and the U.S.

Toxic treatments: Lead lingers in folk remedies

Tue, 05 Jun 2018 14:48:52 -0400

Credit: K. Cantner, AGI.

Lead is one of the most ubiquitous heavy metals in nature, and, for decades, it was a common ingredient in a wide range of consumer goods. After numerous studies detailed its toxicity and concluded there is no safe amount of lead in the human body — especially in children — new laws and regulations curbed its use dramatically. And yet, lead still appears in many products, particularly cosmetics, traditional medicines and folk remedies that are often lightly regulated.

Stable isotopes offer novel methods of disease detection

Thu, 14 Dec 2017 16:38:41 -0500

NASA astronaut Peggy Whitson holds the American record for the longest cumulative time spent in space at 665 days. Bone loss is a serious concern for space travelers — in less than half a year, they can lose up to a third of what a nonspace-traveler would expect to lose in a lifetime — so NASA monitors the bone density of astronauts. Credit: NASA.

Astronauts lead dangerous lives. Besides the inherent risks of blastoff, re-entry and space flight, astronauts experience myriad physical changes from spending time in microgravity. They’re frequently monitored for kidney stones, for example, and for muscle and bone loss that result from a prolonged lack of gravity. How to combat the bone deterioration seen during extended time in space is one of the key questions NASA hopes to resolve before sending people on longer missions, such as to Mars.

Benchmarks: December 5, 1952: The Great Smog smothers London

Wed, 15 Nov 2017 21:14:50 -0500

A clear day versus a smoggy day in Beijing. Winter smog can be especially thick and visibility can be reduced to meters. Scientists have recently used smog in Beijing to better understand what happened in London in 1952. Credit: both: Peter Barwick, www.flickr.com/photos/barwick.

On Friday, Dec., 5, 1952, a blanket of thick, yellow smog settled over London, cloaking the city for five days straight. Smog wasn’t uncommon — Londoners called these days “pea-soupers,” based on the yellow-black color — and there were notable smog episodes from the Industrial Revolution (late 1700s) through the 1950s. But the haze of the city’s infamous “Great Smog” of 1952 long overstayed its visit. The lingering smog killed thousands, and its residual effects lasted for decades.

Smokier U.S. West as climate changes

Tue, 15 Nov 2016 11:14:14 -0500

Jia Coco Liu and her team created an interactive map showing counties in the U.S. West most likely to suffer from high wildfire pollution events and elevated dangerous particulate matter. Credit: khanotations.github.io/smoke-map/.

Extended wildfire seasons and larger and more frequent burns will likely be the consequence of the hotter and drier conditions expected to result from climate change. New research shows that this expected surge in wildfires also poses a growing threat to human health.

Kilauea increases asthma risk

Wed, 28 Sep 2016 16:47:35 -0400

Hawaii's Department of Health maintains daily vog alerts and publishes advisories for vog conditions around the state. At the time of this image in 2009, the region west of Hawaii Volcanoes National Park (downwind from the coastal plumes) had a vog advisory for people with respiratory sensitivities. Credit: image taken by the STS-125 crew.

Kilauea may be best known for its picturesque red lava flowing into the ocean, but new research presented this week at the Geological Society of America annual meeting in Denver, Colo., suggests that locally, the volcano may be known for something more dangerous: asthma. The new study links gaseous eruptions from the Hawaiian volcano to increased asthma risk for those living downwind, especially children.

Crippling heat stress projected by midcentury in densely populated regions

Fri, 01 Apr 2016 12:28:56 -0400

Land-surface temperatures, as shown in this false-color NASA MODIS image taken on July 1, 2004, were as high as 59 degrees Celsius during a blistering heat wave over the Iberian Peninsula, while "dry-bulb" air temperatures reached up to 40 degrees. New research suggests that many densely populated parts of the planet will be subjected to "crippling" heat stress by midcentury. Credit: NASA Goddard Space Flight Center.

Extreme heat events, defined by the U.S. Environmental Protection Agency as periods of summer weather that are substantially hotter and/or more humid than is typical for a given location and time, can cause heat stress. Heat stress, an illness that occurs when the body is unable to cool itself via sweating, can lead to cramps, heat exhaustion and — at its most severe — heat stroke, a potentially fatal condition.

Widespread malaria risk from African dams

Thu, 31 Dec 2015 13:46:12 -0500

Map of existing and planned large dams considered in a new study that analyzed rates of malaria infection near the dams in areas where malaria transmission is stable (perennial) versus unstable (seasonal). Credit: Kibret et al., Malaria Journal, 2015.

Large dams cause more than 1 million cases of malaria annually in sub-Saharan Africa, according to the authors of a new study published in Malaria Journal.

How to feed 11 billion people: Addressing the 21st century's biggest challenge

Wed, 30 Dec 2015 10:03:38 -0500

A market in Delhi, India. Credit: Christian Haugen, CC BY 2.0.

In April 2008, violent protests erupted across the impoverished Caribbean nation of Haiti. Enraged by soaring food prices and all-too-frequent hunger pangs, protesters smashed windows, looted shops, barricaded streets with blazing cars and stormed the presidential palace in the capital, Port-au-Prince. The week of violence, during which five people were killed, flared after the cost of staples like beans and cooking oil spiked dramatically and the price of rice nearly doubled in four months, increasing hardships in a nation where 80 percent of the population survives on less than $2 per day.

Does the sun trigger autoimmune disease?

Thu, 08 Oct 2015 10:20:23 -0400

Solar activity may play a role in incidences of rheumatoid arthritis and giant cell arteritis, two autoimmune diseases. Credit: SOHO (ESA & NASA).

For hundreds of years, humans have charted the appearance of sunspots, the changing frequency of which marks highs and lows in the sun’s 11-year solar cycle. Peaks in the solar cycle cause surges in the amount of solar radiation reaching Earth, which can lead to changes in weather and climate, and can disrupt radio signals and electrical grids. Now, researchers have found that the solar cycle may also affect human health, with cases of rheumatoid arthritis and giant cell arteritis seeming to spike in concert with solar fluctuations.

Step one: Soil testing

Thu, 17 Sep 2015 10:23:56 -0400

Several gardening practices can be used to remediate soils to lower lead contamination. Credit: Center for Urban Health.

The first step in planning a community or backyard garden should always be to get the soil tested, getting a read on not only pH and nutrient levels, but possible contaminants like lead and arsenic. “Some cities have public health programs to help residents get their gardens tested for low or no cost, but it’s kind of hit or miss,” says Gabriel Filippelli, a biogeochemist at Indiana University in Indianapolis. Some cities such as Philadelphia have also held one-day “soil kitchen” workshops where people can bring in samples of soil for immediate testing with an X-ray fluorescence instrument.

Toxic Gardens: The long legacy of urban lead

Fri, 04 Sep 2015 11:49:09 -0400

Community gardens (such as the one above in Indianapolis) and playgrounds are common places where children can come into contact with lead-contaminated soils in the urban environment. Remediation at the playground above was funded by the Greater New Orleans Foundation and U.S. Department of Housing and Urban Development. Credit: top: Gabriel Filippelli/Indiana University; bottom: Howard Mielke/Tulane.

From a toxicological point of view, soaring lead levels in the home environment represented one of America’s lowest points — but efforts to improve the situation also led to one of our greatest success stories. After leaded gasoline and lead paints were identified as the culprits behind alarmingly high blood lead levels in children in the late 1970s, the federal government passed legislation banning the metal from these products, and many wide-reaching programs educated the public on how to reduce exposure to lead. By the 1990s, average blood lead levels in children exposed to lead in the home had dropped from 15 micrograms per deciliter of blood to just two.

Marine mammals blamed for first New World tuberculosis

Tue, 09 Dec 2014 12:01:46 -0500

Fur seals in Argentina. Credit: Ricardo Bastida.

When Europeans arrived in the Americas they introduced an array of new infectious diseases that decimated the native populations. Now, a new genetics-based study published in Nature shows that the emergence of tuberculosis in Peru seems to have predated the arrival of the Spanish — and that seals and sea lions may be to blame instead for the ancient infections.

Antibacterial clays could fight superbugs

Mon, 08 Dec 2014 09:40:45 -0500

Clays with antibacterial properties found near Crater Lake in Oregon could eventually lead to new agents in the fight against antibiotic-resistant superbugs like methicillin-resistant Staphylococcus aureus, better known as MRSA, according to a new study.

Mapping how malaria risk changes as new dams go up

Thu, 17 Apr 2014 15:07:58 -0400

Malaria is considered a leading public health problem in Ethiopia, with almost 70 percent of the country’s total population of more than 90 million people at risk from the deadly disease. Now, researchers are studying how hydroelectric dams affect malaria prevalence by combining computer simulations with field data from the Ethiopian countryside. The hope is that the new research could provide fresh insight for malarial management programs.