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Indian Express
31-05-2025
- Health
- Indian Express
Going beyond AQI: study shows why toxicity matters in measuring air pollution
The ability of PM2.5 air pollutants to cause damage to cells increases sharply after concentration levels cross a certain threshold value, new research has found. For Kolkata, where the study was carried out, this threshold value is about 70 micrograms per cubic metre (µg/m³), the study found. Once the PM2.5 concentration crosses this level, its toxicity — or the potential to cause damage to the human body — increases sharply, and continues to rise until the concentration reaches about 130 µg/m³. Toxicity stabilises after that, and further increases in concentration do not lead to an appreciable rise in damage potential. The study, by Abhijit Chatterjee of the Bose Institute, Kolkata, and two of his former PhD students, Abhinandan Ghosh and Monami Dutta, is the first attempt at investigating how toxicity of air pollution changes with concentration levels in Indian cities. ('Contrasting features of winter-time PM2.5 pollution and PM2.5-toxicity based on oxidative potential: A long-term (2016–2023) study over Kolkata megacity at eastern Indo-Gangetic Plain', Science of the Total Environment, December 2024) This is not to suggest that at concentrations below 70 µg/m³ in Kolkata, air pollution is benign and does not pose any threat to human health. Pollution is damaging at lower concentrations as well, but it becomes much more toxic after crossing the threshold value. At lower concentrations, the body copes better with the adverse impacts of inhaling pollutants. After the threshold level, however, the body's defence mechanisms are overwhelmed, and the pollutants are able to cause greater damage to cells, particularly the respiratory systems which are affected first. When pollutants are inhaled, the body's immune system tends to fight back through the release of Reactive Oxygen Species (ROS), which are chemicals used by immune cells to neutralise foreign substances. When larger concentrations of pollutants are inhaled, greater amounts of ROS are released. The problem is ROS is damaging for the body's cells as well. Therefore, as a natural counter-defence mechanism, the body produces another set of chemicals, called antioxidants, that protect the cells against ROS. However, antioxidants are present in small quantities, and take time to build up. So, while they are able to effectively deal with smaller amounts of ROS, they are helpless when ROS is produced in large amounts. This leads to an imbalance in the body, a situation called oxidative stress, which leaves the internal cells prone to damage from excess ROS. 'The PM2.5 pollution level is well understood and established in every city in India… We wanted to see how the level of toxicity increases with the increase in pollution level,' Prof Chatterjee said. 'We know that when PM levels increase, there are several consequences, such as haze, dust, and visibility reduction. But how far does toxicity surge? We did not know. Though India has its standards of PM2.5 and PM10, we don't have a threshold value in terms of oxidative stress in the human body. That's where we wanted to determine the standard,' he said. According to Prof Chatterjee, 'When the PM2.5 concentration level exceeds about 70 µg/m³, its potential to create oxidative stress increases steeply, mainly because of the presence of some specific chemical components like those coming from biomass or solid waste burning. The components from vehicular emissions also help increase oxidative stress, but this is much less compared to biomass burning.' The threshold levels at which toxicity sees a sharp rise is expected to vary from city to city, mainly due to the differences in the composition of the air pollutants. In some cities, vehicular emissions might be the biggest contributor to pollution; in other places, biomass burning might be significant. Air quality standards are framed in terms of their concentration, not toxicity. In India, for example, a PM2.5 concentration level of 40 µg/m³, averaged over a year, is considered safe. On a daily basis, a concentration of 60 µg/m³ is considered safe. However, the harmful impacts of air pollution on human health depend not just on concentration, but also on toxicity, which takes into account factors like chemical composition of pollutants. In Kolkata, for example, the threat that annual PM2.5 concentrations of 50 or 60 µg/m³ poses is not going to be very different from the one posed by a concentration of 30-40 µg/m³. But alarm bells must go off once a level of 70 µg/m³ is reached. In other cities, this would be different. This study can thus make the case for toxicity-based air quality standards, which can trigger targeted warnings/emergency actions once the threshold concentration is breached. Dipanita Nath is interested in the climate crisis and sustainability. She has written extensively on social trends, heritage, theatre and startups. She has worked with major news organizations such as Hindustan Times, The Times of India and Mint. ... Read More
Yahoo
19-05-2025
- Health
- Yahoo
Scientists make concerning discovery about memory of bees: 'We really might be in a tricky position'
Scientists have found that microplastic pollution may impair the memory of bees, interfering with their ability to remember floral scents and locate flowers, which could lead to lower pollination rates. As The Washington Post reported, researchers have discovered that microplastics are impacting the brains of honeybees and other pollinators, including bumblebees, according to a study published in the journal Science of the Total Environment. Microplastics can also physically block plant structures, preventing pollen from being deposited and the plant from being pollinated. Since microplastics are virtually everywhere in the environment — air, waterways, soil, and even remote locations such as the Pyrenees — it's easy for bees to ingest or inhale the particles while foraging for nectar and pollen. Microplastics are deposited in nature from the incorrect disposal of trash, such as water bottles and food wrappers that contain plastic, as well as stormwater runoff and direct discharge from wastewater or industrial plants, among other sources. As the particles break down into smaller pieces, they travel through the air and land on flowers. When bees unknowingly consume microplastics, it can have a devastating impact on their health, disrupting their gut bacteria and immune systems, according to another study in Science of the Total Environment. "If plastic is adding to all the stressors that pollinators are facing already, I think we really might be in a tricky position," Thomas Cherico Wanger-Guerrero, an agroecologist at Agroscope, an agriculture research center in Switzerland, told the Post. Since bees are so vulnerable to microplastic exposure, the particles are likely to end up in honey. The Post reported that Turkish scientists found microplastics in most honey samples taken. In Germany, commercial honey was found to contain about five microplastic particles per teaspoon. Plastics have been linked to a wide range of human health problems, including hormone disruption, kidney and heart disease, birth defects, and an increased risk of cancer. Since people are already frequently exposed to plastics, the detection of plastics in honey is bad news, as it could lead to further health issues. If bees aren't pollinating as many flowers and crops, our food supply could be at risk. According to the U.S. Department of Agriculture, pollinators play a crucial role in feeding the world, with scientists estimating that around 35% of the world's food crops rely on pollinators for growth. Bees also pollinate native plants and contribute to the overall health of ecosystems. Do you worry about air pollution in and around your home? Yes — always Yes — often Yes — sometimes No — never Click your choice to see results and speak your mind. With bees facing numerous environmental stressors, including habitat loss, rising global temperatures, and pesticide exposure — all of which have been linked to declining bee populations — microplastics are a dire threat to the species. Researchers have found that biochar — a popular soil amendment used on farms — removed nearly 93% of plastic particles from study samples, showing promise for global food supplies. Additionally, scientists have developed an ultra-thin film that can reduce crop losses and prevent microplastics from polluting the soil. Wanger-Guerrero told the Post that "the urgency to mitigate exposure of nature to plastic" can't be overstated, as plastic affects humans, wildlife, and the environment. We can help bees by reducing our plastic use in daily life and opting for eco-friendly alternatives, such as switching from single-use water bottles to reusable ones. Recycling plastic is also essential to reduce waste and keep microplastics out of the environment. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
Yahoo
12-05-2025
- Science
- Yahoo
Scientists uncover shocking revival of ancient threat beneath melting ice: '[What's happening] in the Arctic doesn't stay in the Arctic'
The Arctic could increasingly become the site of animal-to-human disease transfer, a study published in the journal Science of the Total Environment suggests. As the ice melts, scientists warn, more zoonoses may spread. The co-authors of the study, published in December 2024, outline several factors that make the Arctic an area of concern when it comes to zoonoses — infectious diseases that can be transmitted from animals to humans. Rising global temperatures have the potential to connect — and amplify — them all. Due to these rising temperatures, arctic ice is melting. As ice sheets disappear, humans and wildlife face issues like rising sea levels and the related effects of habitat and biodiversity loss. For example, when species that require solid ice on which to live, reproduce, and hunt lose their grounds to melting, their populations decline, with impacts further down the food chain too. Habitat and biodiversity loss can also sponsor the spread of disease by increasing animal-human interactions. Additionally, scientists think that biodiversity loss can "[mean] that the species that remain are the competent ones, the ones that are really good at transmitting disease," infectious disease ecologist Jason Rohr explained to the New York Times in May 2024. But scientists are also concerned with the melting of something called permafrost — a layer of ground that can remain frozen for long periods of time, trapping ancient microbes and other pathogens as well as pollutants in an icy prison. As permafrost melts, scientists caution that we may see even more disease spread. According to the Environmental Protection Agency, permafrost temperatures in Alaska "have increased at an average rate of 0.6°F per decade" from 1978 to 2023. We already know that the impacts of Arctic ice melt are felt globally. Melting ice can influence shifts in weather patterns, with the potential to cause extreme weather events everywhere. And as Khaled Megahed Abass, a co-author of the December 2024 study, underscored in a news release, "[what's happening] in the Arctic doesn't stay in the Arctic." The co-authors wrote in the study that "Arctic inhabitants are often in close contact with, and dependent on, wildlife for sustenance." Food supplies could be another route of transmission for pathogens already given a leg up by habitat loss, biodiversity loss, and permafrost melting. The study also notes that diseases originating in the region "have more potential to spread globally than ever before." This means there's every chance the whole world could be affected at the pandemic level. Do you worry about air pollution in and around your home? Yes — always Yes — often Yes — sometimes No — never Click your choice to see results and speak your mind. Melting permafrost can affect the whole world in another way too. When microbes newly unlocked from their deep freeze begin to consume organic matter, they can produce gases like methane and carbon dioxide. The more this heat-trapping pollution is released into our atmosphere, the more we're set to contend with the rising temperatures that cause ice melt in the first place. The team's study calls for more monitoring and protection in the Arctic, highlighting the importance of integrating traditional Indigenous knowledge. The authors also note the importance of public health campaigns and improved infrastructure to inform and support those who might be impacted first. Permafrost could merit special attention for its potential to unleash ancient microbes, mysterious pathogens, more warming, and untold damage. But it's also just one element in a complex system of climate issues. "Climate change is not only melting ice—it's melting the barriers between ecosystems, animals, and people," Abass said. "This study shows how environmental disruption can directly impact human health." No one person can halt temperatures rising around the world, but concerned citizens of Planet Earth can work together to identify steps that, especially when taken collectively, have a chance to curb the crisis. Switching to electric vehicles en masse, advocating for community solar programs, and championing pro-environment policies can add up. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
Yahoo
06-04-2025
- Health
- Yahoo
Researchers stunned by behavior shift in unique fish species: 'Need for more comprehensive research'
Common pollutants have a significant impact on fish activity, a new study has found. Researchers from Sultan Qaboos University in Oman studied the effects of common pollutants — chemicals, noise, and light — on zebrafish. Their findings were published in the April edition of Science of the Total Environment. The fish were exposed to various levels of fluoxetine (often sold under the brand name Prozac) along with artificial light at night and simulated motorboat noises. These were chosen to simulate common stressors that fish deal with, especially when living in urban environments. Those exposed to fluoxetine were less bold, while those exposed to nighttime light pollution were bolder and more active. Motorboat noises also tended to make the fish more active. Perhaps most interesting is how the factors at play seemed to interact to produce different results in the fish. Fluoxetine exposure seemed to reduce the activity typically seen as a consequence of noise and light pollution. And the effects of the motorboat noises on the fish depended heavily on when the animals were exposed to the sounds. "Fish that were tested with noise first often reacted more strongly than those that were initially tested without noise, suggesting that noise increased the stress of adaption to a new environment," the study's co-authors wrote. The authors believe this is the first study to determine how chemical, noise, and light pollution can interact to affect fish, which is important because it's rare that pollution is isolated in the real world. Previous studies have shown that low amounts of fluoxetine could threaten fish, as it "reduced the body condition and sperm vitality of male guppies over multiple generations," according to The Guardian. It's not uncommon for fluoxetine — and other chemicals — to enter waterways when people flush pharmaceuticals down the toilet, so studying the drug's potential effects on marine life makes sense. A number of studies have also shown how the light and noise created by human activity can wreak havoc on wildlife. One study found that hundreds of mammal species no longer follow their normal activity patterns and have drastically changed their daily schedules due to human disruptions. This new study points to the dangers that urban sprawl can pose to wildlife. It also emphasizes the importance of continuing to explore how several factors, which may typically be studied individually, might overlap to impact an ecosystem. Do you worry about air pollution in your town? All the time Often Only sometimes Never Click your choice to see results and speak your mind. "Environmental stressors often co-exist in the real world and the limited number of studies in this area underscores the need for more comprehensive research," the paper's co-authors wrote. Learning more about the potential for human activity to influence animals could help inform policies and decision-making that shape where and how we live. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
Yahoo
31-03-2025
- Health
- Yahoo
Scientists discover major health risk after studying popular food source: 'We're just providing the numbers'
Waterfowl like ducks and geese are some of the most hunted animals in the northeast United States, but a recent study has revealed something alarming regarding these creatures. As summarized in a post from Cornell University on nearly every bird tested in a large-scale survey of commonly hunted species was contaminated with harmful chemicals — and these pollutants could pose health risks not just to wildlife but also to the people who eat them. Researchers analyzed over 100 waterfowl harvested by hunters across the northeast, finding dangerous chemicals in every single bird. The contaminants included polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and per- and polyfluoroalkyl substances (PFAS) — the latter often called "forever chemicals" due to their persistence in nature and the human body without breaking down. Species like mallards and American black ducks had higher levels of contamination, likely because of what they eat and where they feed. Canada geese and wood ducks had lower levels, but none of the bird species was without pollutants. This has led experts to reconsider the current health advisories that recommend no more than two meals of wild-caught waterfowl per month. "This provides a really good baseline," said Krysten Schuler, a senior researcher on the study, which was published in the journal Science of the Total Environment. "We're not telling people what to eat or do. We're just providing the numbers." This is both a wildlife and public health issue. Exposure to PCBs and PFAS is linked to increased cancer risk, hormone disruption, and developmental issues. These chemicals are known to accumulate in the body over time, which is particularly worrisome for communities that regularly eat wild game. PFAS are especially dangerous. These substances are in everyday items like non-stick cookware, waterproof clothing, and have even been tied to immune system issues, liver damage, and increased cholesterol. The good news? This study will give health officials the data they need to update outdated consumption guidelines and better protect hunters and their families. Do you worry about the longevity of EV batteries? For sure Not really Not at all I've never thought about it Click your choice to see results and speak your mind. It also highlights the urgent need to clean up polluted environments where waterfowl live and feed — often areas already stressed by habitat loss and wetland destruction. You can take steps, too. Limiting your intake of wild-caught waterfowl, especially from high-risk areas, is a smart move. Supporting PFAS-free products, reducing reliance on plastic, and advocating for stricter regulations on toxic chemicals can help build momentum for change. Join our free newsletter for weekly updates on the latest innovations improving our lives and shaping our future, and don't miss this cool list of easy ways to help yourself while helping the planet.
