Connect with us

Science

Gold mining with mercury threatens health of communities miles downstream

Published

on

May 28 (UPI) — Small-scale gold mining using mercury in the Peruvian Amazon threatens the health of communities 100 miles or more downstream, according to new research.

In 2015, scientists collected hair and blood samples of mercury from more than 1,200 Peruvian households in 23 communities, some close to mining operations and others more than 100 miles away. The research team returned a year later to retest the same households.

The data, published Thursday in the Journal of Exposure Science and Environmental Epidemiology, showed adults and children living in native villages were more likely to have higher mercury exposures than non-native Peruvians.

The diets of many native communities in Peru feature large amounts of freshwater fish. Mercury pollution concentrates in large fish at the top of the food chain.

“Assumptions about exposure are not reliable,” study co-author Caren Weinhouse, an assistant professor at Oregon Health and Science University, said in a news release.

Previous mercury contamination surveys have mostly focused on people living closed to gold mining activity, but the latest research suggests the risk of exposure extends far beyond a mine’s immediate surrounding.

“If you look more closely, it turns out your first instinct may be wrong,” Weinhouse said.

A parallel study, published last week, showed Peruvian children living with the highest levels of mercury in their blood score lower on IQ tests and experience anemia, a dearth of hemoglobin that makes it harder for their oxygen to carry blood throughout the body.

“If you were going to have a high IQ anyway, you’ll probably still have a higher IQ after exposure, but for kids at risk for impairment, a few points can make a difference,” said Duke University graduate student Aaron Reuben, co-author of the neurocognitive study of Peruvian children.

While native communities downstream from gold mining were at greater risk of mercury exposure, researchers found elevated mercury levels in the blood samples of more than half the general population.

“Our paper describes some plausible biological pathways for that to happen,” said William Pan, an associate professor of environmental sciences and policy at Duke. “But really, this is something we need to understand a bit more.”



Source link

Science

Researchers, growers seek vanilla production in Florida

Published

on

ORLANDO, Fla., Aug. 11 (UPI) — Growers and researchers in Florida hope the aromatic vanilla bean can provide a lucrative, high-margin crop for the state’s farmers.

The University of Florida is heading research into vanilla, which comes from a tropical orchid and carries a hefty price around the world.

The goal is to determine how well the plants grow in Florida’s subtropical climate, where the dominant crop — citrus — has suffered from destructive diseases and hurricanes that have shut groves and put growers out of business.

Already, the university reports that hobbyists, bakers and breweries are calling to line up more vanilla production.

“The interest in this as a new crop is huge,” said Alan Chambers, assistant professor of tropical plant genetics at the university’s research station south of Miami.

“Our biggest problem right now is growers can’t find enough plants. We have people calling and asking to buy the beans we’re growing, and we say you have to wait a couple of years.”

Chambers knows that vanilla can grow in Florida because four native species of the vanilla orchid plants exist, but none of the native types produces authentic vanilla.

So, he’s started with the most common commercial species, vanilla planifolia, the beans from which Madagascar and Mexico export in large quantities. Chambers has 150 of the plants ready to distribute to community center gardens and other growers as far north as Tampa.

Florida will never be able to compete globally for vanilla due to the cost of labor, but there’s a big demand for specialty vanilla, he said.

“We’d be looking at extremely high quality, similar to the limited vanilla production in Hawaii,” Chambers said. “We’re hearing from brewers, herbalists, bakers and aroma extractors.”

Chambers also helped a Miami area grower, attorney Abrahm Smith, obtain 800 of the vanilla plants for Smith’s small, 8-acre farm. They take up about one-quarter of an acre.

“It’s a hobby farm for me, but if vanilla works, it will be great because it has a very high-profit margin,” Smith said. “I should be able to make as much from that quarter-acre as I do from 6 acres of fruit trees we’ve planted.”

That high margin is what drove the crop to become one of Madagascar’s top exports, but the bean is not processed on the island. Much of the bean crop is processed when it reaches the United States, where it is primarily used as a food and drink flavoring.

The price of vanilla has fluctuated wildly in recent years with weather conditions in Madagascar, from $600 per 2.2 pounds of beans in 2018 to $350 for that amount in June.

The United States is the largest importer of vanilla beans. Given the high value of the crop, and Florida’s struggles with citrus, the University of Florida funded Chambers’ research with a $75,000 grant.

Chambers also advises a separate project led by private industry that collects funds from interested growers to provide thousands of the vanilla plants from a nursery in Orlando.



Source link

Continue Reading

Science

Math models developed by Alan Turing help scientists explain bird behavior

Published

on

Aug. 11 (UPI) — In a new study, researchers in Britain used math models developed by famed mathematician Alan Turing to figure out why flocks of long-tailed tits separate themselves into different parts of their habitat.

Many birds form what are called home range patterns, but scientists have struggled to explain why non-territorial passerine segregate themselves.

For the study, scientists at the University of Sheffield tracked the movements of long-tailed tits across the woodlands they called home. After collecting enough data for patterns to emerge, researchers used Turing-inspired models to determine what causes the segregation.

The models deployed by Sheffield researchers were similar to those Turing developed to show how patterns in nature, like stripes of a zebra or a leopard’s spots, can emerge naturally from a uniform state.

The new analysis, published this week in the Journal of Animal Ecology, showed long-tailed tits, when segregating themselves across the landscape, were less likely to avoid places where they had previously interacted with relatives.

The passerine birds, however, were more likely to steer clear of places where they’d previously encountered larger flocks. The birds also showed a preference for the center of the woodlands.

“Mathematical models help us understand nature in an extraordinary amount of ways and our study is a fantastic example of this,” Sheffield doctoral student Natasha Ellison, lead author of the new study, said in a news release.

Scientists had previously used Turing models to understand the movement patterns and distribution of territorial animals, but this is the first time the same mathematical models have helped researchers understand the spacing and movements of a non-territorial species.

“Long-tailed tits are too small to be fitted with GPS trackers like larger animals, so researchers follow these tiny birds on foot, listening for bird calls and identifying birds with binoculars,” Ellison said.

“The field work is extremely time consuming and without the help of these mathematical models these behaviors wouldn’t have been discovered,” Ellison said.



Source link

Continue Reading

Science

Increasing indigenous property rights could help save the rainforest

Published

on

Aug. 11 (UPI) — To protect the Amazonian rainforest, new research suggests full property rights for tribal lands be extended to Brazil’s indigenous communities.

For the study, researchers at the University California, San Diego, used satellite data of vegetation coverage in the Amazon rainforest to study deforestation patterns between 1982 and 2016. Scientists compared the results of their mapping efforts with Brazilian government records of indigenous property rights.

The analysis, detailed Tuesday in the journal Proceedings of the National Academy of Sciences, showed land owned fully and collectively by local tribes featured a 66 percent reduction in deforestation rates.

“Indigenous traditional land use, based on collective ownership, has been associated with the preservation of a land’s biodiversity,” researcher Kathryn Baragwanath, postdoctoral candidate in the political science department at UCSD, told UPI.

One study published earlier this year showed land stewardship by indigenous communities was associated with greater levels of carbon sequestration.

Baragwanath said these positive ecological impacts are strengthened when indigenous communities have the full scope of property rights and legal tools to defend tribal lands from commercial interests.

“These legal rights ensure that the boundaries can no longer be contested, the territory is registered in the national land registry, the government is constitutionally responsible for protecting the territories and the territorial resources are considered to belong to indigenous peoples,” she said.

When conducting their analysis, Baragwanath and researchers accounted for variables besides indigenous property rites — including proximity to roads, mining projects and rivers, elevation, population density and rainfall.

In Brazil, the process of gaining full property rights, called homologation, is complex — at least partially because government agencies there have been slow to review applications, researchers said.

Often, as the process plays out at a snail’s pace, commercial interests will start illegal mining or logging, so they can later argue that they’ve established “productive use of land,” researchers said.

To protect the Amazon and the region’s remaining forests, Baragwanath suggests Brazil’s government strengthen their environmental agencies.

“Public policy should focus on granting full property rights to the indigenous peoples who have not yet received their rights,” she said.



Source link

Continue Reading

Trending