Visiting Beijing or New Delhi for as little as a week could expose travelers to high levels of air pollution, a new study finds.
Researchers say young, healthy adults who travel internationally can experience coughing and breathing difficulties upon returning home from smog-filled cities.
Some adults’ lung function was reduced by as much as 20 percent.
But visitors to cities with low levels of pollution, such as London and Prague, experienced few to no symptoms.
The team, from New York University School of Medicine, says it’s important to reduce levels of air pollution quickly because the number of tourists traveling abroad is set to reach 1.8 billion by 2030.
A new study from NYU Langone Health has found that visitors to highly polluted cities experience symptoms such as coughing and difficult breathing that took a week to recover from. Pictured: A layer of pollution hovers above Los Angeles, October 2017
‘We had several reports that tourists were feeling sick when visiting polluted cities,’ said senior investigator Dr Terry Gordon, a professor in the department of environmental medicine at NYU Langone Health.
‘So it became important for us to understand what was really happening to their health.’
For the study, published in the Journal of Travel Medicine, the team looked at 34 adults between ages 18 and 29 who were traveling abroad from New York City.
None of the men or women had preexisting health conditions and all of them were taught how to measure their lung function and heart rates on their own.
Pollution was measured by levels of atmospheric particulate matter, which makes up what we commonly call ‘smog.’
Cities with more than 100 micrograms per cubic meter of particulate matter were considered highly-polluted.
Those that fell into this category were predominantly located in East and South Asia and included Xian, China; Ahmedabad and New Delhi, India; and Rawalpindi, Pakistan.
Some places – like Beijing and Shanghai, in China, and Milan, Italy – were considered heavily polluted only during certain months of the year.
Moderately-polluted cities had between 35 and 100 micrograms per cubic meter, and cities with low levels of pollution had less.
The standard set by the Environmental Protection Agency is 12 micrograms per cubic meter.
Lower levels of air pollution were mostly found in European cities including Prague, Czech Republic; Copenhagen, Denmark; Reykjavik, Iceland; London, England; Oslo, Norway; San Sebastian, Spain; Stockholm, Sweden; and Geneva, Switzerland.
New York City was also shown to have relatively low levels of air pollution – partly due to strict regulations, its location on the east coast, and weather patterns.
Lung function was reduced by six percent on average, and by as much as 20 percent in people that visited polluted cities, the researchers found.
Additionally, they reported up to five respiratory symptoms, such as coughing and difficult breathing, while those who visited less polluted cities had few to no symptoms.
Dr Gordon suggests that international travelers visiting smog-filled cities wear masks and avoid travel during certain months.
For example, he advises against visiting New Delhi in the winter months because farmers pile and burn their crops, releasing more toxic particles into the air.
‘What travelers should know is that the potential effects of air pollution on their health are real and that they should take any necessary precautions they can,’ said Dr MJ Ruzmyn Vilcassim, a postdoctoral fellow in the department of environmental medicine.
Although the participants recovered from their illnesses, the team says follow-up research is needed to study potential long-term effects or there would be a greater impact from longer stays.
Researchers plan to study those are more vulnerable to air pollution’s harmful effects such as those who are elderly or have asthma.