Damaging particulate pollution has been found on the fetus-side of placentas in pregnant women. However, some researchers question whether this actually means it can cross the placenta barrier.
Pollution emitted from vehicles, factory smokestacks or coal power plants may be able to penetrate the placenta in pregnant women, researchers said on Tuesday.
Black carbon particles were discovered on the fetus-facing side of placentas, according to a study published in Nature Communications.
"Our study provides compelling evidence for the presence of black carbon particles originating from air pollution in human placenta," the authors said.
The study found the concentration of particles in placentas was highest for women most-exposed to pollution in their day-to-day lives.
Researchers from Belgium's Hasselt University used a novel scanning technique to search for soot-like black carbon in the placentas of 28 new mothers. They were hoping to shed light on how exposure to the tiny particles lead to premature births and low birth weight.
Scientists led by Tim Nawrot said the results showed that "black carbon particles are able to translocate from the mothers' lungs to the placenta." There was no evidence of pollution particles in the fetus itself.
What too much traffic does to our environment — and to us
Traffic jams are bad for the environment, the economy and our health. Here are the worst consequences due to traffic congestion — and the places where people suffer the most.
Image: Getty Images/AFP/Y. Kadobnov
Testing your patience
Getting into a traffic jam is every driver's nightmare. Endless minutes (or worse: hours) in which nothing's moving forward can turn what should be a short car-ride into a seemingly never-ending odyssey. But congested streets aren't just annoying for commuters — they have far-reaching consequences.
Image: picture-alliance/dpa/A. März
Higher emissions
Turn off your engine when you get into a traffic jam! You'll save fuel after 20 seconds of standing still already. Letting your engine run while your car's idling burns one liter of fuel an hour, according to Germany's technical inspection agency TÜV Süd. A higher fuel consumption rate means that more CO2 is blasted into the atmosphere, which we should avoid if we want to fight global warming.
Image: picture-alliance/dpa/I. Fassbender
Germany's congestion capital
Germany saw roughly 745,000 traffic jams in 2018, according to German automobile club ADAC. That's a three-percent increase compared to 2017. According to GPS-maker TOMTOM's last survey, Cologne's streets were the most congested (as shown above). On average, travel time increased by more than a third because of congestion, compared to free flowing traffic.
Image: picture-alliance/dpa/R. Vennenbernd
Traffic breakdown in L.A. and Moscow
GPS-maker INRIX uses different calculations and has identified Munich as Germany's traffic jam capital. Drivers there were stuck in congestion for an average of 51 hours a year. That's nothing compared to the world leaders: The world capital of traffic jams is Los Angeles, where drivers were stuck in traffic for 102 hours a year, followed by Moscow (pictured here) and New York with 91 hours each.
Image: Getty Images/AFP/Y. Kadobnov
Endangering your health
People who are stuck in traffic frequently have to deal with serious health problems. When traffic isn't flowing as it should, your body releases stress hormones. Your immune system is weakened and your blood pressure rises. People who are frequently stuck in traffic jams, like commuters, are even likely to develop burnout syndrome.
Image: picture-alliance/dpa/F. Cirou
Billions in economic losses
According to INRIX, the costs caused by traffic jams in Germany amounted to 80 billion euros in 2017. Goods don't reach their intended recipients on time and more fuel is burned. Both companies and private drivers suffer financially. Traffic jams "threaten economic growth and stunt quality of life," INRIX head economist Graham Cookson said.
Image: picture-alliance/Zumapress/G. Falvey
Ride-sharing apps made things worse
For a while hopes were high that ride-sharing services like Uber would bring down traffic. If people could easily get a ride, maybe they'd leave their own cars in the garage more often! But traffic researcher Bruce Schaller found out that the opposite was true in US cities. People took Uber instead of the subway or their bikes, while car owners kept driving their own vehicles.
Image: picture alliance/dpa/Imaginechina/Da Qing
Traffic just one contributor to air pollution
Afghanistan's capital Kabul is also dealing with congested streets. But that's not the only factor contributing to dangerous air pollution. In winter residents have taken to burning coal, car tires and trash to generate heat. Add to that diesel generators and many, many cars and you get smog that Afghanistan's National Environmental Protection Agency (NEPA) calls "deadly."
However, a leading placenta expert who wasn't involved with the new research cautioned that the results are not proof the soot actually crossed the placenta to reach the fetus — or that it's responsible for any ill effects.
Still, "just finding it at the placenta is important," Dr. Yoel Sadovsky of the University of Pittsburgh Medical Center told the Associated Press. "The next question would be how much of these black carbon particles need to be there to cause damage."
The placenta nourishes a developing fetus and shields it from damaging substances in the mother's bloodstream.
