A long wrapup today, starting with a new danger posed to ocean creatures, and moving on to yet another frog-killing pesticide, new links between pesticides and low IQs in children exposed to them, flame retardant hazards to young folks, more fracking worries, mining threats to America’s natural wonders, a plague of rats, and, finally, some good news about the world’s oldest sweetener.
Ocean noise pollution kills squids
As far back as 1983, scientists had established links between the Navy’s use of low frequency sonar and previously mysterious deaths of dolphins and other marine mammals.
Now new evidence has appeared than links low frequency ocean sounds with the deaths of cephalopods, reports Portugese marine scientist Michel André, writing for the Ecological Society of America:
Noise pollution in the oceans has been shown to cause physical and behavioral changes in marine life, especially in dolphins and whales, which rely on sound for daily activities. However, low frequency sound produced by large scale, offshore activities is also suspected to have the capacity to cause harm to other marine life as well. Giant squid, for example, were found along the shores of Asturias, Spain in 2001 and 2003 following the use of airguns by offshore vessels and examinations eliminated all known causes of lesions in these species, suggesting that the squid deaths could be related to excessive sound exposure.
Michel André, Technical University of Catalonia in Barcelona, and colleagues examined the effects of low frequency sound exposure—similar to what the giant squid would have experienced in Asturias—in four cephalopod species. As reported in an article published in Frontiers in Ecology and the Environment (e-View), a journal of the Ecological Society of America, all of the exposed squid, octopus and cuttlefish exhibited massive acoustic trauma in the form of severe lesions in their auditory structures.
The researchers exposed 87 individual cephalopods—specifically, Loligo vulgaris, Sepia officinalis, Octopus vulgaris and Illex coindeti—to short sweeps of relatively low intensity, low frequency sound between 50 and 400 Hertz (Hz) and examined their statocysts. Statocysts are fluid-filled, balloon-like structures that help these invertebrates maintain balance and position—similar to the vestibular system of mammals. The scientists’ results confirmed that statocysts indeed play a role in perceiving low frequency sound in cephalopods.
André and colleagues also found that, immediately following exposure to low frequency sound, the cephalopods showed hair cell damage within the statocysts. Over time, nerve fibers became swollen and, eventually, large holes appeared—these lesions became gradually more pronounced in individuals that were examined several hours after exposure. In other words, damage to the cephalopods’ auditory systems emerged immediately following exposure to short, low intensity sweeps of low frequency sound. All of the individuals exposed to the sound showed evidence of acoustic trauma, compared with unexposed individuals that did not show any damage.
“If the relatively low intensity, short exposure used in our study can cause such severe acoustic trauma, then the impact of continuous, high intensity noise pollution in the oceans could be considerable,” said André. “For example, we can predict that, since the statocyst is responsible for balance and spatial orientation, noise-induced damage to this structure would likely affect the cephalopod’s ability to hunt, evade predators and even reproduce; in other words, this would not be compatible with life.”
Another pest killer link to amphibian deaths
The world’s amphibians are dying off at unprecedented rates, posing a critical threat to ecosystem across the globe.
Tyrone Hayes, a UC Berkeley biologist, has demonstrated that atrazine, one of the world’s best-selling plant killers, has been killing off amphibians, resulting in a brutal attack by the leading manufacturer [previously], and now comes word that yet another agricultural chemical, this time a fungicide, may be contributing to the die-off.
From Craig Pittman of the St. Petersburg Times:
Two years ago some University of South Florida researchers began studying the effects of the most widely used fungicide in the country to see if it might kill more than just fungus.
Turns out it’s also a pretty effective frog-icide.
“We were completely surprised to see it basically killed everything,” said Taegan McMahon, the lead researcher on the study, which was published this week in a scientific journal called Environmental Health Perspectives. Frogs on farms with treated fields, frogs in ponds on golf courses, frogs in the back yard — the fungicide could be lethal to any of them, the study suggests.
“We don’t know what the effect on humans could be,” she added. “And we use it heavily in Florida.”
The fungicide, chlorothalonil, sold under such names as Bravo, Echo and Daconil, is used to treat farmers’ fields, lawns and golf courses and is an ingredient in mold-suppressing paint.
It’s part of the same chemical family, organochlorines, as the banned pesticide DDT. It is known to cause severe eye and skin irritation in humans if handled improperly.
Chlorothalonil kills mold and fungi by disrupting the respiratory functions of the cells, explained Jason Rohr, an assistant professor who co-authored the study and heads up USF’s Rohr Ecology Lab. At this point the researchers don’t know if that’s how it kills frogs, too, he said. They just know it’s lethal.
“We’ve previously studied a variety of other pesticides, such as atrazine, as well as herbicides and insecticides,” Rohr said. “We haven’t seen one with nearly the mortality that we’ve seen with chlorothalonil.”
Frogs and other amphibians play an important role in the food chain, which is why scientists began sounding the alarms in the early 1990s when they discovered many were disappearing. An estimated one-third of the world’s 6,300 amphibian species are threatened with extinction, with the blame being pointed at climate change, loss of habitat, chemical use by humans and a spreading fungus — just the sort of thing a fungicide would kill.
It killed nearly 90 percent of the frogs, no matter what species, McMahon said. When they doubled the dose, it killed all of them. Even weaker concentrations harmed the frogs’ immune and liver systems and may have altered their stress hormone levels.
A spokeswoman for Syngenta, the Swiss manufacturer of Bravo and Daconil, challenged the study’s findings.
Pesticides linked to lower IQs
Some truly ominous news confirms another link between human health and our habit of dosing the world with chemicals to kill things we don’t like comes from Kerry Sheridan of The Sydney Morning Herald:
High levels of pesticide exposure in pregnant women have been linked to lower IQs in their children, according to three separate US studies.
Two studies were done in New York City and a third was in Salinas, a farming area of northern California. All spanned nearly a decade, tracking levels of pesticide in expectant mothers and testing nearly 1,000 children up to age nine.
Researchers looked at exposure to a family of pesticides known as organophosphates, which are commonly used on fruit and vegetable crops. The reports are published in the journal Environmental Health Perspectives.
In the California study involving 392 kids, “researchers found that every tenfold increase in measures of organophosphates detected during a mother’s pregnancy corresponded to a 5.5 drop in overall IQ in the seven-year-olds.”
The differences held even after researchers accounted for factors such as education, family income, and exposure to other environmental contaminants, the study, released on Thursday, said.
Researchers at Mount Sinai, New York measured 400 women and their children from 1998 onward.
They found that “exposure to organophosphates negatively impacted perceptual reasoning, a measure of non-verbal problem-solving skills” between the ages of six and nine.
They also found that about one-third of the mothers studied carried a gene variant that made them less able to metabolize the pesticides, and that the negative effects in children were limited to this subgroup.
The third study, done by researchers at New York’s Columbia University, looked specifically at one pesticide, chlorpyrifos, which was widely used to kill cockroaches and termites until it was banned from residential use in 2001.
In the sample of 265 minority children born before the ban took effect, higher prenatal exposure was linked to lower intelligence scores and poorer memory.
Children in the top 25 percent of exposure levels scored 5.5 percent lower in working memory tests and 2.7 points lower in IQ.
Flame retardant levels soar in California kids
Because synthetic fabrics burn hot and, unlike cotton, melt and stick to the skin when set ablaze, clothing manufacturers regularly treat them with infusions of flame-retardant chemicals.
The compounds are also used in electronic gear, which may heat up and catch fire.
The compounds have been subjected to precious little testing for adverse impacts on human health, and some of the few researchers working in the field are right here at UC Berkeley.
Last year Cal epidemiologists reported on findings of high levels of flame-retarding polybrominated diphenyl ethers [PBDEs] in the blood of pregnant women in California’s Salinas Valley.
According to a report from Marla Cone of Environmental Health News in January 2010, elevated blood levels coincided with reduced fertility, and animal studies have also linked the compounds to lower sperm rates and altered hormone levels in males.
Six months later, the team reported that they had found links between the retardants and levels of thyroid hormones in the blood of pregnant women.
As Science Daily reported at the time:
“This is the first study with a sufficient sample size to evaluate the association between PBDE flame retardants and thyroid function in pregnant women,” said the study’s lead author, Jonathan Chevrier, a UC Berkeley researcher in epidemiology and in environmental health sciences. “Normal maternal thyroid hormone levels are essential for normal fetal growth and brain development, so our findings could have significant public health implications. These results suggest that a closer examination between PBDEs and these outcomes is needed.”
In a just-published account at Environmental Health News, Cone reports on the newest study from the Berkeley research team:
Mexican American school children in California’s Salinas Valley are contaminated with seven times more flame retardants than children in Mexico and three times more than their own mothers, according to a new scientific study.
The 7-year-olds in the low-income farm community had more of the chemicals in their bodies than almost all other people tested worldwide. Household dust, contaminated with flame retardants released by old furniture, is likely the major source of their exposure.
“The levels in young children noted in this study present a major public health challenge,” wrote the researchers, directed by University of California, Berkeley School of Public Health epidemiologist Brenda Eskenazi. “While this challenge is particularly pronounced in California children, it is also relevant to other regions in the U.S.” because the flame retardants are used in furniture and other items sold nationwide.
Health effects of the chemicals are largely unknown, but two studies have linked them to worse fine-motor skills and attention in children, and declines in fertility.
The findings suggest that low income, rather than race or ethnicity, is probably the major factor in determining who is highly exposed to brominated flame retardants. Poorly manufactured or deteriorating furniture may release more of the compounds, which are added to polyurethane cushions to slow the spread of flames when furniture catches fire.
The only people who have been found with higher levels in their bodies were Nicaraguan children living or working on hazardous waste sites, according to the study, which was published online last week in the scientific journal Environmental Health Perspectives.
New fracking concerns reported
Fracking, short for hydraulic fracturing, is the Next Big Thing in natural gas production, a way to get at otherwise inaccessible gas reserves trapped in underground shale deposits to feed our endless hunger for fossil fuels.
Chemically laced water is injected under high pressure through wells drilled deep into the shale formations, freeing the gas. But just what’s in the fluid remains something of a mystery, raising concerns among environmentalists.
It’s controversial [previously], and a fierce debate is raging between critics who charge that it results in massive pollution and defenders [including esnl friend Tad Patzek, who observes that “Without fossil fuels, all modern renewable energy sources would be dead before arrival.”] who say that, properly used, it offers a tool to help us survive the transition off of our fossil fuel hungers as reserves dwindle.
The problems, of course, lie with those two invariables of human experience: unintended consequences and human error.
First, the latest from the unintended consequences side of the equation, from Matthew Heller of FairWarning:
The controversial natural gas extraction technique known as fracking releases so much methane that it wipes out the supposed advantage of the fuel in slowing down climate change, a new study by Cornell University researchers concludes.
Natural gas, which is abundant in the U.S., has been widely touted and has gained political support as a cleaner-burning alternative to oil and coal.
But according to the Cornell study, to be published in the journal Climatic Change, methane emissions from shale gas production are at least 30 percent more than — and perhaps more than twice as high — as those from conventional gas production. Those higher emissions largely result from fracking, or hydraulic fracturing, the process of injecting water, sand and chemicals into a gas well to open up subterranean cracks that release natural gas from shale rock formations.
All told, the greenhouse gas emissions from the production and use of shale gas challenge “the logic of its use as a bridging fuel over coming decades, if the goal is to reduce global warming,” wrote the Cornell researchers, who were led by Robert Howarth, a professor of ecology and environmental biology. “We do not intend that our study be used to justify the continued use of either oil or coal, but rather to demonstrate that substituting shale gas for these other fossil fuels may not have the desired effect of mitigating climate warming.”
The study also stated that the greenhouse gas “footprint” for shale gas “is greater than that for conventional gas or oil when viewed on any time horizon, but particularly so over 20 years. Compared to coal, the footprint of shale gas is at least 20 percent greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years.”
And on the human error side of the equation, this from the Associated Press:
A natural gas company has suspended “fracking” at all of its wells throughout Pennsylvania until it figures out the cause of a spill in the northern part of the state.
Chesapeake Energy Corp. said Thursday that crews have significantly reduced the flow of chemical-laced water from its out-of-control well near Canton in Bradford County.
Spokesman Brian Grove says that the exact cause of Tuesday night’s breach is unknown, but that it’s located in a wellhead connection.
Thousands of gallons of drilling fluids were spilled. They escaped containment, crossed over farm fields and went into a stream.
The spill has since been stopped, but the questions remain.
Mining threat to national parks, monuments
As nature’s reserves of vital mineral supplies dwindle, the unthinkable becomes thinkable as our all-consuming industrial machinery begins to starve from the lack of vital inputs.
And now the hunger for two minerals, gold and uranium, is threatening some of America’s remaining natural wonders.
And once again, it looks like the Obama administration is caving in to the interests of its corporate sponsors.
From Suzanne Goldenberg, US environment correspondent for The Guardian:
America’s most majestic landscapes – from the Grand Canyon to Mount Rushmore – are at risk because of booming global demand for uranium, a new report warns.
The report, by the Pew Environment Group, calls on the Obama administration to overhaul antiquated laws governing the mining of gold and uranium, and offer permanent protection to national landmarks.
The administration must decide by July whether to extend a two-year respite on thousands of mining claims in areas around the Grand Canyon, Mount Rushmore, Joshua Tree national park and the area around Yosemite national park. If it does not, there is nothing to stop mining interests from drilling on its claims around the canyon, the report warns.
“These claims are all still active, and there is nothing right now that the government can do to prevent them from becoming mines,” said Jane Danowitz, who works on public lands protection for Pew.
Obama moved to protect public lands soon after coming to the White House, calling a two-year halt to mining in sensitive areas.
The interior secretary, Ken Salazar, must now decide whether to extend the ban. But environmental organisations argue Obama had already demonstrated reluctance to take on a fight with Republicans over protecting America’s natural heritage.
Under a spending deal reached last week, Obama agreed not to use money from a newly launched wilderness initiative that would have protected 7.3 million acres of land from drilling.
The 38-page Pew report is posted here [PDF].
Australia suffers from a plague of rats
In addition to devastating its wheat crop, Australia’s torrential rains have spawned yet another environmental disaster, this time of the four-legged variety.
From BBC News:
A mass migration of rats is under way into the inland deserts of Australia after a run of high rainfall seasons, scientists say.
The native long-haired rat, or Rattus villosissimus, normally lives in the Barkly Tableland of the Northern Territory and in western Queensland.
But now it has been spotted in Alice Springs for the first time in 25 years.
“Some of them get up to about 30cm [12in] long – fair lump of a rat,” livestock manager Chris Giles said.
“They will run around and hide under a little bit of shrub there, and you can get pretty close to them,” Mr Giles, a stockman on the Northern Territory’s Lake Nash Station, told Australia’s ABC News.
“I nearly caught one the other day.”
Peter McDonald, acting scientist with Northern Territory Biodiversity Conservation, said the phenomenon was a “huge event” which he attributed to a run of consecutive good, high rainfall seasons.
“It is unusual in the rodent world but Rattus villosissimus are unique in that way and they are pretty famous for their eruptions,” he added.
“Probably the only similar expansion by a rodent is seen in the lemmings in the northern hemisphere with their irruptions. There is nothing else in Australia which irrupts over such a large area.”
Alice Springs generally has no rats because of its arid climate.
Finally, the good news we promised, and it’s a honey
It’s even been shown to be effective against Methicillin-resistant Staphylococcus aureus [MRSA], the terrifying bug that’s been nicknamed “flesh-eating bacteria.”
From Jeremy Laurance of The Independent:
Manuka honey, the premium product found on fashionable breakfast tables, could play a role in the battle against antibiotic-resistant superbugs, scientists reported [12 April].
Honey is known to have antiseptic properties but the antibacterial potency of manuka honey, from New Zealand, is 10 to 50 times more powerful. It has been shown to stop the growth of antibiotic-resistant Staphylococcus aureus – the superbug that causes MRSA.
Manuka honey is derived from nectar collected by honey bees foraging on the manuka tree in New Zealand and is included in modern wound-care products such as dressings and ointments available on NHS prescription. However, its antimicrobial properties have not been fully exploited, according to researchers.
Laboratory studies by Professor Rose Cooper and colleagues at the University of Wales Institute, Cardiff, show that manuka honey interacts with three bacteria that commonly infect wounds – MRSA, Pseudomonas aeruginosa and Group A streptococci. “Our findings suggest that manuka honey can hamper the attachment of bacteria to tissues which is an essential step in the initiation of acute infections. Inhibiting attachment also blocks the formation of bio-films, which can protect bacteria from antibiotics and allow them to cause persistent infections,” Professor Cooper said.
“Honey can make MRSA more sensitive to antibiotics – effectively reversing antibiotic resistance. This indicates that existing antibiotics may be more effective against drug-resistant infections if used in combination with manuka honey.”
The long-term aim was to develop products combining honey with antibiotics that could be applied directly to infected wounds to speed healing and prevent the spread of suberbugs to other patients in hospital, she said. The findings were presented at a meeting of the Society for Microbiology in Harrogate.
“We will still need antibiotics taken systemically [orally] for blood infections. But we may be able to develop products with low concentrations of antibiotics and honey than can be applied directly to a wound.”
For more on biofilms, see here.