Bacteria found in China’s severe smog are multiplying causing the layer of pollution to thicken and may even pose a threat to human health, scientists have warned.
Big cities – particularly in the developing world – like Beijing are shrouded in a heavy, toxic smog from coal burning and vehicle exhaust.
Smog season begins around November in the country, when homes and power utilities burn more coal for power and heating, which gets trapped over the city.
Experts say that airborne bacteria may cause disease and affect allergies by releasing volatile organic chemicals as waste.
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Bacteria found in China’s severe smog could be multiplying and even pose a threat to themselves, scientists have warned. Big cities like Beijing are shrouded in a heavy, toxic smog which comes from pollution as a result of coal burning and vehicle exhausts (stock image of Shanghai)
Professor Maosheng Yao from Peking University in Beijing wanted to understand how the bacteria within smog interact with each other.
It follows a 2016 study that found clumps of bacteria were common during severe hazes in the skies above Beijing.
His team collected samples from the air during four different types of smog episodes ranging from low to high in 2017 and 2018 and examined the bacteria present.
Not only did they find that there were a far larger amount of bacteria when the haze was worse but that up to 70 per cent of the microorganisms could survive and multiply in the lab.
They also found that the microorganisms changed as the smog got worse, with some species becoming less common while others became more plentiful.
‘This is the first time that I’ve actually seen information like this,’ Frank Kelly, a Professor of Environmental Health at King’s College London who was not involved in the study, told NewScientist.
‘We’re introducing these various bacteria into the environment, maybe for the first time, without fully understanding the implications.’
Smog season begins around November in the country, when homes and power utilities burn more coal for power and heating, which gets trapped over the city. Pictured here, two women wear protective masks in Shanghai (stock image)
Scientists found a larger amount of bacteria when the haze was worse and that up to 70 per cent of the microorganisms could survive and multiply in the lab. Pictured here, people ride bikes or walk on the iconic ancient wall in Xi’an, northwest China’s Shaanx (stock image)
Professor Yao suggests that the reason for this is that the bacteria are feeding on pollutant chemicals like sulphates and nitrates.
Although it sounds like the bacteria feeding on the chemicals is a good thing, Professor Yao says it just replaces one pollutant with another.
The bacteria may also form more particulate matter, which is one of the most dangerous forms of pollution, by clumping together.
Professor Yao found that the microbes release volatile organic chemicals as waste.
WHAT ARE VOLATILE ORGANIC COMPOUNDS AND WHAT ARE THEIR EFFECTS ON HEALTH?
Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids.
VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects.
Concentrations of many VOCs are consistently higher indoors, up to ten times higher, than outdoors.
VOCs are emitted by a wide array of products numbering in the thousands.
Organic chemicals are widely used as ingredients in household products.
Paints, varnishes and wax all contain organic solvents, as do many cleaning, disinfecting, cosmetic, degreasing and hobby products.
Fuels are made up of organic chemicals.
All of these products can release organic compounds while you are using them, and, to some degree, when they are stored.
The ability of organic chemicals to cause health effects varies greatly from those that are highly toxic, to those with no known health effect.
As with other pollutants, the extent and nature of the health effect will depend on many factors including level of exposure and length of time exposed.
Health effects may include include: Eye, nose and throat irritation; headaches, loss of coordination and nausea; damage to the liver, kidney and central nervous system.
Some organics can also cause cancer in animals and some are suspected or known to cause cancer in humans.
He also suggested that the airborne smog bacteria may cause disease and affect people’s allergies.
The researchers traced many of the species back to a pharmaceutical plant that uses engineered bacteria to make drugs and a local wastewater treatment plant, which uses bacteria to process waste.
He warned that we need to control the industrial use of bacteria to help limit air pollution.
Researchers found that the microorganisms changed as the smog got worse, with some species becoming less common as others became more common. Here, traffic and pollution on motorway near the financial district of Xian (stock image)
The researchers traced many of the species back to a pharmaceutical plant that uses engineered bacteria to make drugs and a local wastewater treatment plant, which uses bacteria to process waste (stock image)