Dear EarthTalk: Are there ways living organisms can be used to fix pollution? ~ M.L., via email
Pollution remains one of the most significant environmental challenges, contaminating air, water and soil and posing risks to human health. Traditional cleanup methods, like chemical treatments and mechanical removal, often come at a high cost and sometimes harm the environment further. So scientists have turned to bioremediation, a process of using living organisms to break down and remove pollutants. This is proving to be a cost-effective and sustainable solution for fighting contamination across our ecosystems.
One of the most promising applications of bioremediation involves microorganisms like bacteria and fungi, which are capable of breaking down harmful substances into less toxic forms. Some bacteria, like Alcanivorax borkumensis, thrive on oil spills, consuming hydrocarbons and helping to restore marine environments. Other species, like Pseudomonas bacteria, can absorb heavy metals from contaminated soil and water, reducing the toxicity of industrial waste sites. Fungi, like Phanerochaete chrysosporium, can degrade complex pollutants such as dioxins and pesticides. Scientists are also developing genetically modified microbes to enhance bioremediation efforts. Scientists design these engineered organisms to target specific pollutants, breaking them down more efficiently than their natural counterparts. “We could start trying to predict what compounds a particular bacterium/enzyme [combination] can use from the genome sequence,” says David Leys, a scientist who has worked on detoxification for many years.
In addition to microorganisms, certain animals also play a vital role in cleaning up pollution. Oysters and mussels act as natural water filters, absorbing heavy metals and microplastics from aquatic ecosystems, improving water quality while also serving as indicators of environmental health. Pollinators like bees and butterflies can accumulate pollutants in their bodies, which help provide insight into contamination levels. Studying these animals helps researchers track the spread of pollutants and develop strategies for mitigating their challenges. The effectiveness of these organisms depends on environmental conditions like temperature, pH, and nutrient availability.
People can advance bioremediation techniques by supporting sustainable cleanup efforts and scientific research. By spreading awareness about these methods and advocating for funding in environmental science, people can help accelerate the adoption of natural pollution cleanup solutions. “The knowledge gained from the research will allow scientists to engineer the organisms and their chemical processes to target specific man-made toxins,” Leys says. Advancements in genetic modification and synthetic biology will likely make bioremediation a widely used method in the coming years.
MORE INFORMATION: smithsonianmag.com/innovation/new-understanding-toxin-loving-organisms-may-help-tackle-pollution-180953159/; sciencedirect.com/topics/agricultural-and-biological-sciences/bioremediation.
♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
Dear EarthTalk: What is mariculture and why are proponents so bullish on it as a solution to environmental challenges? ~ Peter Manchin, Atlanta, GA
Growing demand for seafood adds more pressure to ocean populations. Mariculture has an alternative that can help mitigate environmental challenges and even climate change. This type of aquacultural practice cultivates marine species in their natural habitats. Like conventional land-based agriculture, farms are carefully monitored and use a variety of pens, nets and cages to centralize the farmed species. Among the organisms are mollusks, crustaceans and finfish, all which are a popular staple for seafood.
Traditionally, seafood production involves catching these animals in their natural habitats, a process that entirely removes organisms from the ecosystem. If demand is high, overfishing can greatly disrupt the wild populations and reduce the long-term viability of seafood industries. Biodiversity will also plummet if this trend continues. In the 2022 Food and Agriculture Organization Report, researchers found that 35 percent of fish were overfished, causing many populations to decline and reach endangered levels.
Mariculture is a very promising solution to these impacts due to its regenerative capabilities and controlled approach to food production. Most mariculture species are born in hatcheries or taken in small amounts from the wild, leaving the natural populations relatively untouched and free of any human-induced pressures. As Robert Jones, Global Aquaculture Lead at The Nature Conservancy, explains, “[Marine] aquaculture can be one of the more resource-efficient means of animal protein.”
There have also been developments toward transforming mariculture into a way to fight climate change. Since oceans absorb around 30 percent of carbon dioxide emissions, adding marine plants like seaweed to farms can accelerate this carbon sequestration. That said, mariculture isn’t perfect. Farming in open waters can create a lot of waste from feces, uneaten food or chemicals. Also, accidents are much more detrimental to the ecosystem, causing disease spread and invasive species if the organisms ever get into the wild. Nonertheless, researchers continue to restructure their approach to mariculture. A report by Ad Hoc Technical Expert Group on Mariculture noted how selecting farm sites with strong water circulation can help disperse waste and mitigate this issue. There has also been increasing supervision and protocols regarding farm species’ health, which can reduce the possibility of disastrous escapes.
To support mariculture and contribute to a future of sustainable seafood, make wiser seafood choices that promote responsible practices. The Monterey Bay Aquarium’s Seafood Watch can provide many helpful resources for finding sustainably sourced fish. You can also encourage businesses to adopt mariculture products or supporting investment and research to integrate mariculture.
MORE INFORMTION: https://www.seafoodwatch.org/.
♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
Dear EarthTalk: How is air quality across the U.S. these days? ~ Paul Jackson, Washington, DC
Air quality is defined as the degree to which the air of a set place is pollutant-free. In the United States, air quality is measured through the Air Quality Index (AQI) created by the U.S. Environmental Protection Agency (EPA). The AQI uses six categorizations of air quality, from Green (0-50) to Maroon (301<); the higher the index, the greater the pollution and health concern. To the EPA, air values below 100 are adequate, while above 100 means unhealthy air, especially affecting minority and low-income groups who, according to the American Lung Association, are disproportionately affected by air pollutants.
In 1970, President Nixon passed the Clean Air Act, creating federal and state regulations on emissions from both industrial and mobile sources. This regulation drastically improved American air quality. Since the 1970s, the emissions from key pollutants like carbon monoxide, lead and sulfur dioxide have decreased by 78 percent. EPA data shows that even through prioritizing public health and regulating contamination, “the U.S. economy remained strong, growing 272 percent over the same time.”
U.S. air has improved in recent decades, but it must still address concerns. In 2023, some 140 million Americans lived in areas below AQI standards. Moreover, with recent wildfires and extreme heat waves, this number will increase by 50 percent in coming decades. Despite federal regulations, air pollution grew between the years 2010 and 2016, and because the EPA recognizes wildfires as “exceptional events” that are not counted against quality, the AQI may not be a completely accurate measure of air quality.
“If we’re going to start thinking about solutions, we have to start combating the origin of the air pollutants, which are wildfires and extreme heat,” Jeremy Porter, head of climate implications at First Street, a research company focused on climate risk financial modeling, told The Guardian.
To help improve air quality in individual spheres, citizens should strive for sustainable and climate-conscious practices in their everyday lives. This can mean investing in electric lawn mowers, using water-based cleaners to avoid harsh chemicals, carpooling to work, using less gas and turning off idling car engines. We can also improve air in our communities by starting recycling programs, setting community-wide emission goals and creating local low-emission zones. National organizing is also a great way to advocate for sustainable environmental practices. This can be done through taking the American Lung Stand Up for Clean Air Pledge, raising awareness on social media, researching local air policy, and urging state representatives to pass conservation-focused bills.
MORE INFORMATION: https://www.lung.org/clean-air/stand-up-for-clean-air/pledge; https://www.airnow.gov/education/what-you-can-do/.
♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
EarthTalk® is produced by Roddy Scheer & Doug Moss for the 501(c)3 nonprofit EarthTalk. See more at https://emagazine.com. To donate, visit https://earthtalk.org. Send questions to: question@earthtalk.org.