Tag Archives: contamination

Agent Orange continues to pollute Vietnam environment, study finds

A “tactical” herbicide used by the US army during the Vietnam War is still affecting the environment and the people relying on it.

The Vietnam government has set up programs to reforest areas heavily affected by Agent Orange. You can clearly see the affected forest line here. Image credits: a_brinr.

“The soils, tropical climate, and network of canals and rivers of southern Vietnam have created one of the most diverse tropical jungles and intensely cultivated landscapes of Southeast Asia,” researchers start off in their study. But, as they continue explaining, it’s also one of the most war-torn areas in modern history. “This paradise has a long history of
numerous wars, foreign occupations, and most recently the Second Indochina War (aka the Vietnam War 1965-1972) which defoliated rain forests and ancient wetland mangroves and left behind contaminated soil and sediment hotspots.”

The Vietnam War was a brutal and unrestrained affair, costing the lives of over 1,000,000 soldiers, and even more civilian casualties. The number of serious injuries it inflicted lied in the millions, and to this day, the area is still recovering. The environment, researchers note, is also still recovering.

In order to be able to operate better in the luxuriant Vietnamese vegetation, the US military deployed a “tactical herbicide”, which became popularly known as Agent Orange. Over 20 million gallons (90 million liters) of Agent Orange were poured over Vietnam’s rainforests, wetlands, and croplands. It defoliated the vegetation, destroyed a significant part of the food crops, and exposed over 4 million people to the harmful effects of the herbicide.

The Vietnam government estimates that as many as 3 million people have suffered illnesses because of Agent Orange, and the Red Cross notes that over 1 million people were left disabled or suffering severe health issues due to exposure. Environmental damage was also huge. In a new study, researchers wanted to assess just how much damage Agent Orange is still causing.

“Existing Agent Orange and dioxin research is primarily medical in nature, focusing on the details of human exposure primarily through skin contact and long-term health effects on U.S. soldiers,” says Ken Olson, professor emeritus in the Department of Natural Resources and Environmental Sciences at University of Illinois and co-author on the article. “In this paper, we examine the short and long-term environmental effects on the Vietnamese natural resource base and how persistence of dioxin continues to affect soils, water, sediment, fish, aquatic species, the food supply, and Vietnamese health.”

US aircraft sprayed 20 million gallons of herbicides across Vietnam during the Vietnam War. Dioxin, a contaminant in Agent Orange, persists today. Image credits: US Army Flight Operations Specialist 4 John Crivello in 1969.

Agent Orange is an equal mixture of two herbicides, 2,4,5-T and 2,4-D, both of which have been noted to be hazardous to human health at significant quantities. The first one was effectively banned in the ’80s, and the second one has been heavily regulated ever since. In theory, neither of the two can last for too long in nature — they tend to disintegrate after a few weeks when exposed to sunlight. However, when they were combined, they produced a dangerous by-product: dioxin TCDD, the most toxic of the dioxin family of chemicals. As it seeps into the soils and plants, TCDD can stick around for decades or even centuries.

Essentially, TCDD attaches itself to organic molecules and clay and clings on to them.

“The pathway begins with the U.S. military spraying in the 1960s, absorption by tree and shrub leaves, leaf drop to the soil surface (along with some direct contact of the spray with the soil), then attachment of the dioxin TCDD to soil organic matter and clay particles of the soil,” says Lois Wright Morton, also a study author.

The team found that TCDD moved around in surface runoff — as the sediment particles were moved around, TCDD went with them. Often, it settled into humid areas like wetlands, marshes, or lakes. From there, it ended up ingested by fish and shrimp, accumulated inside their tissues, and moved up the food chain. Although fishing is technically banned in contaminated areas, the bans have been difficult to enforce, and people still end up ingesting TCDD-contaminated fish. Even 50 years later, new generations are still suffering the effects of TCDD contamination, researchers say, with no clear end in sight.

Researchers mapped the 10 airbase sites where dioxin TCDD is believed to persist at the highest levels. Millions of Vietnamese live in adjacent cities and villages and are exposed to dangerous levels of contamination.

“The worst dioxin-contaminated site in Vietnam is Bien Hoa airbase, which is 30 miles north of Ho Chi Minh City,” Olson says. “After President Nixon ordered the U.S. military to stop spraying Agent Orange in 1970, this is the site where all the Agent Orange barrels remaining in Vietnam were collected. The barrels were processed and shipped to Johnston Island in the Pacific Ocean, where they were incinerated at sea in 1977.”

There are two main approaches to dealing with this contamination. The cheapest — and only one used at a large scale — is landfill storage. However, instead of truly dealing with the problem, this only offers temporary storage, delaying the contamination rather than eliminating it. Researchers suggest another approach: incineration.

It’s a lengthy and costly process, but incinerating contaminated sediments is the only realistic way of dealing with the contamination, researchers conclude.

“While incineration is the most expensive technology currently available, it would eliminate dioxin rather than temporarily store it in a landfill, and incineration would not require future maintenance or treatment. Incineration is one of the most commonly used technologies, having been used to treat soils at more than 150 superfund sites, and is a mature and tested technology,” the authors say.

This serves as yet another reminder of how devastating and long-lasting the consequences of modern war can be. Even 50 years later, the “tactical herbicide” is still doing its job, affecting Vietnam’s environment and human population.

Journal Reference: Kenneth Ray Olson, Lois Wright Morton. Long-Term Fate of Agent Orange and Dioxin TCDD Contaminated Soils and Sediments in Vietnam Hotspots. Open Journal of Soil Science, 2019; 09 (01): 1 DOI: 10.4236/ojss.2019.91001

If we don’t hurry, the life we find on Mars might be from Earth

“There is a ticking clock now,” Princeton astrobiologist Chris Chyba said at last week’s Breakthrough Discuss conference, conducted at Stanford University. The race isn’t to find life on Mars — it’s to find it in time before we contaminate the Red Planet with our Earthly microbial fauna.

Is there life on Mars? Even if there is, is it from Mars? Image credits: NASA / JPL.

We don’t know if there is life on Mars or not. The Red Planet seems like a good candidate, and we’ve found significant evidence that it might have held vast quantities of liquid water on its surface at once point in its geological past — a prerequisite for life as we know it. There’s also a good case to be made against this, with its lack of active tectonics and atmosphere. If Martian life exists, it’s bound to live beneath the surface where it’s shielded from the devastating radiation, and almost certainly microbial. Either way, it’s an exciting area of active research, but we might be on a clock.

With every mission we send to Mars, every lander, and especially with the planned manned missions to Mars, we risk contamination with microbial creatures from Earth. These alien microorganisms (technically, they’re Earth microorganisms, but to Mars, they’d be aliens) could overpower and destroy potentially existing native fauna.

For instance, Elon Musk’s highly anticipated mission to Mars aims to bring people to Mars within the decade, and Boeing CEO Dennis Muilenburg has announced similar plans. For the Martian life, the effects would be unforeseeable — hence Chyba’s remarks. But people weren’t necessarily fond of his idea. Longtime space entrepreneur Jeff Greason, who serves as chairman of the board for the Tau Zero Foundation, poked fun at Chyba:

“If all you want to do with the solar system is look at it, the rest of us would like to borrow it for a while. … There are things to do with these bodies other than science.”

Others have claimed that there’s no reason to believe Earth’s microbes would take over the Martian natives.

“You could terraform Mars, and the microbes on Mars would survive,” said Robert Zubrin, founder and president of the nonprofit Mars Society.

But Chyba makes a very valid point. If we don’t really know what could happen, isn’t it better to take extra precautions? He advocates a precautionary approach, what he calls the Smokey the Bear argument: “Until we know more, let’s be careful.”

To me, this sounds like a sound idea. There are many unknowns when it comes to Mars and its habitability, but we can take measures to limit the potential damage, for instance by ensuring that no microorganisms escape through astronauts’ space suits. If we send people to Mars, microbes are bound to come along for the ride, and the effects can truly be unforeseeable. We shouldn’t just concede that we’re gonna contaminate Mars no matter what.

Lead exposure might be responsible for 10 times more premature deaths than previously thought

A new study suggests that lead exposure may be responsible for nearly 10 times more deaths in the United States than previously thought.

Credit: Wikipedia.

Scientists have discovered that nearly 412,000 deaths each year in the US can be attributed to lead contamination. That number is ten times higher than the Institute for Health Metrics and Evaluation at the University of Washington in Seattle had previously reported.

“Today, lead exposure is much lower because of regulations banning the use of lead in petrol, paints and other consumer products, so the number of deaths from lead exposure will be lower in younger generations. Still, lead represents a leading cause of disease and death, and it is important to continue our efforts to reduce environmental lead exposure,” explained Professor Bruce Lanphear, from Simon Fraser University in Canada.

Lanphear and colleagues estimated that 28.7% of heart disease-related premature deaths in the US could be caused by lead exposure, which comes to a total of 256,000 deaths annually. 

Researchers used data from the Third National Health and Nutrition Examination Survey, which monitored 14,289 US adults for 20 years. Of the 4,422 participants who died by 2011, approximately 18% of them could have been saved by reducing blood lead concentrations to 1.0 micrograms per deciliter.

Compared to those with low lead blood concentrations, people with high lead levels (over 6.7 micrograms) had the risk of premature death from any cause increased by 37%, the risk of cardiovascular death increased by 70%, and double the risk of death from ischemic heart disease.

“Our study calls into question the assumption that specific toxicants, like lead, have ‘safe levels’, and suggests that low-level environmental lead exposure is a leading risk factor for premature death in the USA, particularly from cardiovascular disease,” Professor Lanphear said in a statement.

Lead exposure can contribute to cardiovascular disease by various pathways. Lead affects the epithelial cells of the blood vessels, which increases the chances of developing plaques that can then cause a heart attack. Lead contamination also leads to kidney damage, which causes high blood pressure and probably acts synergistically with plaque formation.
Also, if you live near an airport, your blood lead levels will be a little higher than if you live farther away due to the lead found in the aviation gas used in single piston jets.

“Estimating the contribution of low-level lead exposure is essential to understanding trends in cardiovascular disease mortality and developing comprehensive strategies to prevent cardiovascular disease. Currently, low levels of lead exposure are an important, but largely ignored risk factor for deaths from cardiovascular disease,” said Professor Lanphear.

The team admits that the study’s principal limitation is that the research relied heavily on one blood concentration measurement taken at the beginning of the study period, almost 20 years ago.
“Our reliance on a single blood test as opposed to serial blood tests means that we have underestimated the impact of lead exposure on cardiovascular disease,” Lanphear said. “There are some things in the study design itself that we really couldn’t change.”

The team urges the retirement of lead-contaminated housing, lead-laden jet fuels, lead water pipes, and the reduction of emissions from smelters and lead battery facilities.

“We’ve made tremendous progress in reducing these exposures in the past four to five decades,” Lanphear added. “But our blood levels are still 10 to 100 times higher than our pre-industrial ancestors,” Lanphear concludes.

Scientific reference: Bruce Lanphear , Stephen Rauch, Peggy Auinger, Ryan W Allen , Richard W Hornung. Low-level lead exposure and mortality in US adults: a population-based cohort studyThe Lancet Public Health, 2018 DOI: 10.1016/S2468-2667(18)30025-2

Credit: SLAC National Accelerator Laboratory // Stanford University

Tiny nanotech device purifies water in less than half an hour using the sun

Credit: SLAC National Accelerator Laboratory // Stanford University

Credit: SLAC National Accelerator Laboratory // Stanford University

The single most important survival trick I know is to leave water coming from suspicious sources out in the sun for a couple of days to purify it. It really works because UV rays kill off the bacteria and the water becomes safe to drink — unless of course it was contaminated with chemicals, in which case I’m out of ideas.

But a couple of days can be a long, long time to wait when you’re thirsty. Luckily, there’s this tiny device Stanford and the SLAC National Accelerator Laboratory just invented that drastically accelerates light-powered decontamination.

Clean water in less than half an hour

Half the size of a postage stamp, the tablet water purifier is made out of  molybdenum disulfide (MoS2) films vertically placed on a glass surface. The walls of MoS2 form a maze-like structure on the glass which looks like a fingerprint. MoS2, typically used as an industrial lubricant, is then activated by a photocatalyst — a thin layer of copper — when sunlight hits the wall.

Once activated, a chemical reaction is set in motion that produces reactive oxygen species that kill bacteria.

“Our device looks like a little rectangle of black glass. We just dropped it into the water and put everything under the sun, and the sun did all the work,” said Chong Liu, lead author of the paper published in Nature Nanotechnology.

In controlled experiments, the tablet killed 99.999% of the bacteria littering a 25-milliliter vessel in 20 minutes. If you need more water purified, you just scale the device to match your needs from a bucket to a tank wagon.

Schematic showing how Stanford's tiny black cube works to *kill bacteria*. Credit: SLAC National Accelerator Laboratory

Schematic showing how the tiny black cube works to *kill bacteria*. Credit: SLAC National Accelerator Laboratory

The reason why it works so fast compared to other sunlight-based purifiers is that it uses the full energy spectrum instead of just UV light, which accounts for only four percent. This way, the tiny black cube can absorb 50 percent of the incoming sunlight’s energy — more than enough to power the benign bacteria-killing chemical reaction.

Right now, the device has been proven to work against E.coli and a lactic acid bacteria. There’s no reason it shouldn’t work against a wide swath of other bacterial species, however. Other kinds of pollutants, like chemicals and viruses, could be eliminated with a future release.

“The easiest water we can treat [right now] is in outside activities, when you scoop water from the river and that water is not really cloudy or heavily polluted, but might contain microorganisms,” Liu said. “You can dump in the device and it can kill the bacteria.”

A lot of people will surely welcome it, too. According to the United Nations, more than 780 million people around the world lack access to clean drinking water.

“As a researcher it’s really exciting for us to see that by developing technologies you have the potential to help a lot of people.” said Liu.

Fracking caused widespread contamination in North Dakota, new study finds

Wastewater spills from hydraulic fracking in North Dakota caused widespread water and soil contamination, a new Duke University study finds.

Nancy Lauer and Jennifer Harkness sample water and soil. (Photo: Avner Vengosh)

Nancy Lauer and Jennifer Harkness sample water and soil. (Photo: Avner Vengosh)

Hydraulic fracking involves injecting highly pressurized fluids into subsurface rocks, creating a system of fissures through which the hydrocarbons can escape. There are many environmental issues associated with this technique, one of them being that the entire thing is difficult to control. This was confirmed by Duke researchers.

They were investigating high levels of ammonium, selenium, lead and other toxic contaminants as well brine water very rich in salts. Both soils and water were contaminated this way, and the pollution was traced back to fracking operations.

“Until now, research in many regions of the nation has shown that contamination from fracking has been fairly sporadic and inconsistent,” said Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment. “In North Dakota, however, we find it is widespread and persistent, with clear evidence of direct water contamination from fracking.”

spill1North Dakota is one of the states with the most fracking activity – and this clearly shows. There are numerous instances where pollution was linked to this activity, and the study shows it.

“The magnitude of oil drilling in North Dakota is overwhelming,” Vengosh said. “More than 9,700 wells have been drilled there in the past decade. This massive development has led to more than 3,900 brine spills, mostly coming from faulty pipes built to transport fracked wells’ flowback water from on-site holding containers to nearby injection wells where it will be disposed underground.”

The team analyzed and mapped the distribution of 3,900 spill sites to show how they were associated with the intensity of the oil drilling. They also found radioactive compounds linked to fracking mixed with the brine. This type of contamination is long-termed, raising more concerns for the future.

“Unlike spilled oil, which starts to break down in soil, these spilled brines consist of inorganic chemicals, metals and salts that are resistant to biodegradation,” said Nancy Lauer, a Ph.D. student of Vengosh’s who was lead author of the study. “They don’t go away; they stay. This has created a legacy of radioactivity at spill sites.”

To make matters even worse, they believe that even more spills are happening, but they are not being monitored. They especially raise concerns about spills on tribal lands.

“Many smaller spills have also occurred on tribal lands, and as far as we know, no one is monitoring them,” Vengosh added. “People who live on the reservations are being left to wonder how it might affect their land, water, health and way of life.”

Journal Reference: “Brine Spills Associated with Unconventional Oil Development in North Dakota,” Nancy E. Lauer, Jennifer S. Harkness, Avner Vengosh. Environmental Science & Technology, April 27, 2016. DOI: 10.1021/acs.est.5b06349

Fukushima meltdown isotopes found on U.S. coasts.

The full extent of Japan’s 2011 Fukushima meltdown is still being uncovered, with measured levels of contamination increasing in previously identified sites throughout the North American coast. While it’s still too low to threaten human or ocean life, this confirms that the power plant continues to leak radioactive isotopes researchers report.

Image via deviantart

The Fukushima Daiichi nuclear plant saw wide-scale equipment failure following the 11 March 2011 earthquake and tsunami. The ensuing triple reactor meltdowns and escape of radioactive material on the 12th were so severe that the accident is considered as being second only to the one at Chernobyl.

Researchers at the non-profit Woods Hole Oceanographic Institution have been taking samples of Pacific Ocean water and analyzing them in an effort to monitor and document the aftermath of the accident. The results show that the Fukushima reactors still leaks radioactive isotopes (especially cesium-134) four years after the meltdowns, reports marine radiochemist Ken Buesseler. Trace amounts of these atoms have been found in several hundreds of miles-wide areas of the Oregon, Washington and California coasts as well as offshore of Vancouver Island.

Another isotope, cesium-137, a radioactive reminder of the nuclear weapons tests conducted between 1950 and 1970, was found at low levels in nearly every seawater sample tested.

“Despite the fact that the levels of contamination off our shores remain well below government-established safety limits for human health or to marine life, the changing values underscore the need to more closely monitor contamination levels across the Pacific,” Buesseler said.

In 2014 the Institute reported detecting isotope contamination about 100 miles (160 km) off the norther coast of California as well as off Canada’s shorelines. The latest readings measured the highest radiation levels outside Japanese waters to date some 1,600 miles (2,574 km) west of San Francisco.

The figures also confirm that the spread of radiation to North American waters is not isolated to a handful of locations, but rather a along a stretch of more than 1,000 miles (1,600 km) of shoreline. Currently, reported levels in these areas shouldn’t be dangerous to organisms, but this may change in the future.

Physicians’ stethoscopes more contaminated than their hands

Hygiene is extremely important for hospital workers – regardless of the type of medicine they practice – because they run a high risk of further transmitting any contamination they might have. But now, research has shown that while healthcare workers’ hands are the main source of bacterial transmission in hospitals, physicians’ stethoscopes appear to play a role too.

The work is the first one to compare the contamination levels between hands and stethoscopes, and results are somewhat unsettling, though not entirely surprising. The stethoscope’s diaphragm was more contaminated than all regions of the physician’s hand except the fingertips, while the tube of the stethoscope was more contaminated than the physicians’ back of the hand, claim investigators at the University of Geneva Hospitals.

“By considering that stethoscopes are used repeatedly over the course of a day, come directly into contact with patients’ skin, and may harbor several thousands of bacteria (including MRSA) collected during a previous physical examination, we consider them as potentially significant vectors of transmission,” commented lead investigator Didier Pittet, MD, MS, Director of the Infection Control Program and WHO Collaborating Centre on Patient Safety, University of Geneva Hospitals. “From infection control and patient safety perspectives, the stethoscope should be regarded as an extension of the physician’s hands and be disinfected after every patient contact.”

This doesn’t mean that you should steer clear of any stethoscopes, but it does raise some significant hygiene issues. Stethoscope contamination is not trivial and is comparable to the contamination of healthcare workers’ fingertips, the hand region most implicated in microbial cross-transmission.

However, physicians should be aware of this problem and pay extra attention to disinfecting their stethoscopes.

Journal Reference:

  1. Yves Longtin, Alexis Schneider, Clément Tschopp, Gesuèle Renzi, Angèle Gayet-Ageron, Jacques Schrenzel, Didier Pittet. Contamination of Stethoscopes and Physicians’ Hands After a Physical Examination. Mayo Clinic Proceedings, 2014; 89 (3): 291 DOI: 10.1016/j.mayocp.2013.11.016

Researchers find contamination in Canadian oilsands operation, but aren’t allowed to talk about it

Researchers from Environment Canada (EC) and the University of Alberta have published a study in which they showed contaminants accumulated in the snow near oilsands operations, despite what oil companies are claiming. They also discovered contaminants in precipitation from testing in the region.

University of Alberta scientist David Schindler holds a whitefish with a tumour, collected from the Athabasca watershed.

 

Perhaps even more disturbing is that fact that researchers were discouraged to talk about their results, according to an internal federal document. This was first obvious at a November 2011 conference in Boston, where the results were first published.

“EC’s research conducted during winter 2010-11 confirms results already published by the University of Alberta that show contaminants in snow in the oilsands area,” said a background document about Environment Canada’s latest findings. “If scientists are approached for interviews at the conference, the EC communications policy will be followed by referring the journalist to the media relations … phone number. An appropriate spokesperson will then be identified depending on journalist questions.”

The original study, led by University of Alberta scientists Erin Kelly and David Schindler, analyzed winter snow, and found a direct correlation between contamination and oilsands operations proximity: the highest concentrations were found right next to the field, with levels dropping further away. However, according to the leaked document, which was also in the hands of Environment Minister Peter Kent, instead of the real results, a scripted list of answers was “suggested”, one which claimed that no link was established between levels of contaminants found and any effect on fish.

The document also said that Environment Canada scientist Derek Muir, who was slated to attend the conference in Boston, and another senior department official, Dan Wicklum, would be allowed to answer questions from reporters “if approved by media relations.” The situation is still pretty murky, but the fact that Wicklum took a leave of absence from his senior government position last January to accept a new job as chief executive of a new oil and gas company seems pretty suggestive.

This is quite a dreadful and shameful situation, and one which should never happen in any country – let alone in developed countries such as Canada. There really isn’t a lot of information related to this cover-up, and the one that can be found is often contradictory, so I won’t go any further. I was outraged by this situation, and as soon as I found something else on this matter I’ll be sure to write it down.

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