Residents commute in Beijing as the city is clouded with smog on November 4, 2021. The elderly and those who are vulnerable to the risks of Alzheimer's disease need to protect themselves from air pollution, according to a study conducted by Fudan University that showed long-term exposure to PM 2.5 increased the risk of cognitive impairment.
The study, titled Association of Long-term Exposure to Ambient Air Pollution with Cognitive Decline and Alzheimer's Disease-related Amyloidosis, was published in the May 18 issue of the Journal of Biological Psychiatry.
It concluded that individuals exposed to high levels of PM 2.5 small airborne particles measuring 1.5 micrometers or less in diameter are more susceptible to the risk of getting Alzheimer's, an illness that causes a decline in cognitive thinking, behavioral and social skills. An increase in 20 micrograms per cubic meter of PM 2.5 exposure can increase the risk of cognitive decline by 10 percent.
The study said air pollution can cause neurotoxic reactions and may have adverse effects on cognitive health.
The study provided key molecular epidemiological evidence that PM 2.5 impairs cognitive function through amyloid, a protein in the brain that proves air pollution-induced cognitive decline.
The study was led by teams from the School of Public Health at Fudan University in Shanghai and the university's affiliated Huashan Hospital.
A professor of environmental health at the school and a team leader on the study, Chen Renjie said that Alzheimer's continues to increase with the aging of China's population, and that factors that affect the disease need deeper research.
Based on the research results, he suggested that nursing homes should be located away from air pollution sources.
It is not good that many nursing homes in China are now built in downtown areas where air pollution is more severe due to heavier vehicle emissions. He said that the elderly should be more informed about things such as placing an air purifier in their bedrooms to reduce exposure to air pollution.
The population-based survey involving 31,573 random participants from 22 provinces was used to conduct the study. They looked at cognition ability via questionnaire results, matched against local air quality data for each respondent from 2008 onwards.
From 2017, about 1,100 cognitively unimpaired participants were selected in Qingdao, Shandong province, between the ages of 40 and 90. Tests were carried out on their cerebrospinal fluid, the key bio-sample for Alzheimer's, and determined whether their cognitive functions had been affected by the environment.