The Chronicle

By Alice Loyd

It’s All About Pollution This Time

More than 80% of people living in urban areas that monitor air pollution are exposed to air quality levels that do not meet World Health Organization (WHO) guidelines. The WHO update issued in June 2016 finds the worst exposure in low- and middle-income countries, where 98% of cities with more than 100,000 inhabitants exceed the limits. The survey covers 3,000 cities in 103 countries and assesses particulate matter only—not nitrogen dioxide (NO₂), which at higher temperatures is a gas with a characteristic sharp, biting odor, or ozone (O₃), a beneficial component of the upper atmosphere but a major air pollutant in the lower atmosphere. Regarding measurement of PM2.5s, ultra-fine particles of less than 2.5 microns, the 2016 update shows India with 16 of the world’s 30 most polluted cities. China has improved its air quality since 2011 and now has only five cities in the top 30. For the larger, slightly less dangerous PM10 particles, India has eight cities in the world’s top 30; Nigeria, Saudi Arabia, and Pakistan each have two cities in the top 10. While only a handful of African cities monitor their levels, Onitsha in south-eastern Nigeria is ranked the most polluted city in the world, with 30 times the WHO-recommended level of 20 micrograms per cubic meter. theguardian.com and www.who.int

New satellite datasets, coupled with new and better data analysis techniques, have improved detection of toxic sulfur dioxide (SO₂) emissions. In June 2016 scientists at NASA, Environment and Climate Change Canada, and two universities announced identification of 39 previously unreported and major human-made sources of toxic sulfur dioxide emissions. The previously unreported emission sources, found in the analysis of satellite data from 2005 to 2014, are clusters of coal-burning power plants, smelters, oil, and gas operations found predominantly in the Middle East, but also in Mexico and parts of Russia. Altogether, the unreported and underreported sources account for about 12% of all human-made emissions of sulfur dioxide—a discrepancy that can have a large impact on regional air quality. SO₂ is one of six air pollutants regulated by the US Environmental Protection Agency (EPA). sciencedaily.com and nasa.gov

The EPA rule on mercury still stands. On June 12, 2016, the Supreme Court declined to overturn the EPA national standards to reduce mercury and other toxic air pollution from coal- and oil-fired power plants. The rule, the first national standard for mercury emissions, was finalized on December 16, 2011, and although power plants were given four years to comply, many instead filed legal objections. Last year the Supreme Court ruled that the EPA did not properly consider costs before writing the regulation, but it did not overturn the rule. Subsequently the Court of Appeals for the District of Columbia Circuit decided to let the EPA keep enforcing the measure, which is separate from the Clean Power Plan. On June 12, 2016, the Supreme Court declined to consider a third request from a group of states to overturn it. epa.gov and thehill.com

Lead pollution in US drinking water is a widespread problem. In March 2016, a giant USA Today investigation identified excessive levels of lead contamination over the past four years in nearly 2,000 water systems spanning all 50 states and collectively supplying water to 6 million people. It found 600 water systems showing lead levels topping 40 parts per billion (ppb)—the level of about 400 of the worst samples in Flint, Michigan. Forty parts per billion is more than double the Environmental Protection Agency’s (EPA’s) action level limit, and the EPA has labeled those levels as an “imminent” health threat for pregnant women and young children. usatoday.com That investigation focused on cities with high lead levels that were being reported. In June 2016 a Guardian study showed at least 33 cities across 17 US states may have high lead levels that are unreported, because they have used water testing methods that may understate amounts. The Guardian asked 81 of the most populous cities and towns east of the Mississippi River how they test drinking water for lead. A review of reports found that in the last decade many water departments used testing methods that defied EPA’s guidelines. In 21 cities, testers were instructed to pre-flush water pipes before testing for lead content. In seven cities, testers removed aerators from spouts before running water, which can reduce lead content. In 23 cities, testers were told to run water slowly, which causes less lead to be dislodged from pipes. These lead-reducing methods go against EPA guidelines, and the Flint charges show they may now be criminal acts. The arrest warrants for the men under indictment in Flint includes the charge that they “did improperly manipulate the collection of water samples by directing residents to ‘pre-flush’ their taps by running the water for five minutes the night before drawing a water sample.” theguardian.com

Controlling chlorine-based carcinogens in drinking water may have helped set the stage for lead issues. In March 2016 water experts commented that the recent lead crisis in Flint, Michigan, and in Washington, D.C., in the early 2000s was, in part, the unintended consequence of federal rules released during the late 1990s and strengthened in the mid-2000s to lessen the byproducts of chlorine and other disinfectants linked with increased lifetime cancer risk. To save money, many systems just added ammonia to the mix, to create chloramines—a group of chemicals with its own host of potentially irritating problems. Sheldon Masters, senior environmental engineer at Corona Environmental Consulting, called the situation “warring regulations,” saying, “By meeting the disinfection byproduct rule, you created a problem meeting the lead and copper rule.” Thomas Waite, an environmental engineer at Florida Institute of Technology, commented, “Treatment plants have really got to be serious about the corrosion concept, meaning pH going outside of the plant.” Utilities install costly reverse-osmosis systems to filter out the organic matter that causes the byproducts to form. Treatment plants also can use expensive ozone or ultraviolet light treatment. But chloramines are cheaper, and many plants take that route. The type of chloramine used in drinking water, monochloramine, is mixed into water at levels that kill germs but are still considered safe to drink, according to the EPA. “That’s flat out cheating to do that,” Waite said, “because chloramines are toxic as hell. Just put a goldfish in your water and see how long it lasts.” Flint’s lead disaster was preceded by a switch from Lake Huron to the more corrosive and contaminated Flint River source. Even worse lead problems arose in Washington, D.C., between 2001 and 2004 after a switch from chlorine to chloramine in order to meet EPA disinfectant byproduct rules. floridatoday.com

New studies indicate that the fibers in our clothes could be poisoning our waterways and food chain. Microfibers—tiny threads shed from fabric—have been found in abundance on shorelines where waste water is released. In a report released June 20, 2016, researchers at the University of California at Santa Barbara found that synthetic fleece jackets release an average of 1.7 grams of microfibers each wash. Older jackets shed almost twice as many fibers as new ones. “These microfibers then travel to your local wastewater treatment plant, where up to 40% of them enter rivers, lakes and oceans,” says the report. When Abigail Barrows of the Global Microplastics Initiative tested almost 2,000 aquatic samples, about 90% of the debris was microfibers—both in freshwater and the ocean. Synthetic microfibers are particularly dangerous because they have the potential to poison the food chain. The fibers’ size also allows them to be readily consumed by fish and other wildlife. These plastic fibers have the potential to bioaccumulate, concentrating toxins in the bodies of larger animals higher up the food chain. A 2011 paper by ecologist Mark Browne first called attention to the problem. Browne sampled wastewater from domestic washing machines and estimated that around 1,900 individual fibers can be rinsed off a single synthetic garment. Microfibers are an even more pervasive form of microplastic than microbeads, which were banned in the United States in December 2015. Microbeads are the tiny plastic spheres used as exfoliants in face wash, toothpaste, deodorant and most beauty products. Patagonia, Polartec, and other outdoor companies use recycled plastic bottles to make their synthetic fibers, but now it seems the plastic might ultimately end up in the oceans anyway, and in a more dangerous form. As the Guardian article comments, “Breaking a plastic bottle into millions of fibrous bits of plastic might prove to be worse than doing nothing at all.” theguardian.com and newsweek.com

The goal of cleaning up plastic pollution in the ocean came closer on June 22, 2016, with the unveiling of a 100-meter clean-up boom prototype. The Dutch government and marine contractor Royal Boskalis Westminster of the Netherlands joined efforts to produce and test the idea envisioned in 2012 by then-teenager Boyan Slat, Dutch inventor, entrepreneur, and aerospace engineering student. The system will be installed 12 nautical miles off the Dutch coast where it will undergo sensor-monitored tests for the next year. Anchored at depths of up to 4.5 kilometers by a cable sub-system, the vulcanized rubber barrier will passively corral floating trash into a V-shaped cone by means of the ocean’s natural currents. Although some trash may be caught during the North Sea prototype test, collecting plastic is not its objective. The sponsors hope to learn how well the floating barrier fares in extreme weather at sea—the kind of conditions the system will eventually face when deployed in the Pacific. The boom, the project of The Ocean Cleanup of which Slat is founder and CEO, is the key ingredient of the organization’s ten-year plan to break up and remove the Great Pacific Garbage Patch. ecowatch.com and theguardian.com

Microbes that eat plastic may become another way to address plastic pollution. In March 2016 a team of Japanese scientists reported finding a species of bacteria that eats polyethylene terephalate, or PET—the type of plastic found in most disposable water bottles. More than 50 million tons of PET is produced globally each year, and it has been particularly resistant to biodegradation. A research team from Kyoto Institute of Technology and Keio University collected 250 PET-contaminated samples from a plastic bottle recycling site. They found that decomposition was indeed taking place amid the sediment, soil, and wastewater, and eventually they identified the bacteria responsible: Ideonella sakaiensis. A community of the microbes could break down a thin film of PET over the course of six weeks at a temperature of 86 degrees Fahrenheit. One ocean scientist, Tracy Mincer at the Woods Hole Oceanographic Institution in Massachusetts, said it was not clear whether or not this knowledge would help keep plastics out of the ocean. Mincer said, “I don’t see how microbes degrading plastics is any better than putting plastic bottles in a recycling bin so they can be melted down to make new ones.” But he added, “The research could make it easier to identify other microbes with degrading capabilities.” latimes.com  The first study to provide detailed evidence of bacterial degradation of plastic in an animal’s gut was published in Environmental Science and Technology in September 2015. It showed that the tiny mealworm, which is the larvae form of the darkling beetle, can subsist on a diet of Styrofoam and other forms of polystyrene. news.stanford.edu 

Doctors, scientists and health advocates are calling for more aggressive regulation of household chemicals. A growing body of research suggests that chemicals used to make plastic more flexible, fruits and vegetables more abundant, and upholstery less flammable may pose a threat to the developing brain. Most chemicals in use today were not adequately tested for safety before being allowed on the market, said Dr. Jeanne Conry, an obstetrician-gynecologist and a past president of the American College of Obstetricians and Gynecologists. “Before we can prescribe medicine, we have to prove it’s safe,” she said. “So how come with the chemical industry, we assume everything is safe and have to prove there’s harm?” Publishing in the July 2016 issue of Environmental Health Perspectives, a coalition of health professionals wants the chemical industry to prove a chemical is safe, rather than waiting on the medical and scientific community to prove it is harmful. “We’re saying, shift the burden of proof,” Dr. Conry said. The chemicals singled out by the coalition are widely used.

• Organophosphate Pesticides: Banned for residential use, they are still permitted on crops like fruit, vegetables, wheat, soy, and corn.
• Flame Retardants: Research shows children exposed prenatally to higher levels of flame retardants had lower IQs and higher hyperactivity scores.
• Lead: Old homes and pipes often still contain lead that gathers in dust and leaches into water. Even low blood levels are associated with lower intelligence and attention deficits.
• Phthalates: They cross the placenta during pregnancy, and prenatal exposure has been linked to problems with attention and intellectual deficits. Six phthalates are banned in toys and child care products, but they are still widely used in products ranging from food packaging to personal care products and building materials.
• Combustion-Related Air Pollutants including nitrogen dioxide, particulate matter, benzene and formaldehyde, and polycyclic aromatic hydrocarbons (PAHs): Air pollutants can cross the placenta, and prenatal and early childhood exposure has been linked with preterm birth and low birth weight, developmental delays, inattention, and reduced IQ. com and niehs.nih.gov

Even plastic labeled as food-safe by the Food and Drug Administration (FDA) can leach highly toxic chemicals. Researchers at the University of Maine found that fish kept for 48 hours in food-grade polyethylene plastic bags (PE1 and PE2) contained high concentrations of nonylphenol (NP), a common chemical used as a plasticizer in industry and commercial products. All fish kept in PE2 died by day eight, while all fish survived in the glass bowls and Teflon bags of the control treatment. Toxicity was found to vary among products having the same label. plasticsoupfoundation.org

Pesticides continue to be advanced as an explanation of Brazil’s microcephaly epidemic. While the culprit has been declared officially to be the mosquito causing Zika Virus Disease (ZVD), New England Complex Systems Institute (NECSI) scientists issued a report on June 27, 2016, calling for that assumption to be reevaluated. The report refers to a study of nearly 12,000 pregnant women infected with Zika in Colombia, published June 15 in the New England Journal of Medicine. For the 616 women in whom ZVD was diagnosed in the third trimester, 82% of their infants were born at term with a normal birth weight, 2% were born at term with a low birth weight, 8% were preterm, and 1% died during the perinatal period. No cases of microcephaly or brain abnormalities had been reported in this group by the date of publication. Seven percent were still being followed at time of publication.nejm.org The NECSI report analyzes this study and concludes that the four cases of Zika and microcephaly that have been observed in Colombia up to April 28, 2016, are just what would be expected without ZVD. (Countries with no reported infections of 2-in-10,000 births gives exactly four cases.) The study also notes that until April 28 there had been a total of about 50 microcephaly cases in Colombia, of which only four were connected with Zika. necsi.edu Even in Brazil, many cases of microcephaly are not related to ZVD. In late January 2016 as Brazilian officials began compiling the data from the 4,180 reported Zika-related microcephaly cases that had been reported since October 2015, in the first 732 of the cases they found that more than half either weren’t microcephaly, or weren’t related to Zika. washingtonpost.com

Earlier this year much attention was given briefly to an appeal from a group in Brazil and Argentina called “Physicians Against Fumigated Towns” that charged insecticides with causing the Zika outbreak. It reported Brazil fumigates against adult Aedes using Malation, a carcinogenic organophosphorate compound according to WHO; Paraguay acquired thousands of tonnes of clorpyriphos, which it said affects the developing brain of fetus and newborns, in order to kill mosquitoes; and Argentina uses pyrethroids, a little less toxic but banned in Europe because of its effect on humans. The physicians wrote, “Massive spreading using planes, as the governments of Mercosur (a trade bloc agreement between Argentina, Brazil, Paraguay, Uruguay, and Venezuela) are considering, is criminal, useless, and a political manoeuver to simulate that actions are taken. The basis of the progress of the disease lies in inequality and poverty, and the best defence are [sic] community-based actions.” reduas.com The pesticide pyriproxyfen has received the most attention as an alternate explanation for microcephaly. It is applied to drinking water in some parts of Brazil to kill the larvae of the mosquitos that transmit Zika, but the World Health Organization (WHO) has emphatically denied that possibility, declaring on the website, “When people drink water from containers that have been treated with pyriproxyfen, they are exposed to the larvicide—but in tiny amounts that do not harm their health. Moreover, 90%-95% of any larvicide ingested is excreted into the urine within 48 hours. This product has been used since the late-1990s without being linked to microcephaly.” who.int Nevertheless, because pyriproxyfen is an analogue for insect juvenile hormone which is cross reactive with retinoic acid, which is known to cause microcephaly, NECSI, the Swedish Toxicology Sciences Research Center, and the physicians group in Brazil and Argentina have each called for further studies of the potential link between pyriproxyfen and microcephaly. sciencedaily.com

The thinning in the ozone layer above Antarctica is starting to heal. A study published in June 2016 in the journal Science shows what the researchers have called “the first fingerprints of healing” of the Antarctic ozone layer. A team including scientists at Massachusetts Institute of Technology (MIT) and University of Leeds in the United Kingdom carried out detailed measurements of the amount of ozone in the stratosphere between 2000 and 2015. Using data from weather balloons, satellites, and model simulations—as well as satellite measurements of sulfur dioxide emitted by volcanoes, which can also enhance ozone depletion—they tracked meteorological changes, such as temperature and wind, which can shift the ozone hole back and forth. They were able to show that the ozone hole has declined compared to its peak size in 2000, shrinking by more than 4 million square kilometers by 2015. British scientists first noticed a dramatic thinning of ozone in the stratosphere some 10 kilometers above Antarctica in the mid-1980s. In 1986, US researcher Susan Solomon showed that ozone was being destroyed by the presence of molecules containing chlorine and bromine that came from chlorofluorocarbons (CFCs). These gases were found in everything from hairsprays to refrigerators to air conditioning units. The situation in Antarctica has been slowly improving since the global ban on the use of CFCs in the Montreal Protocol in 1987, and according to the authors this new study shows the ozone layer is now actively growing larger again. bbc.com and sciencedaily.com