Dec. 22 (UPI) -- People exposed to formaldehyde at work for extended periods may be at higher risk for thinking and memory problems as they age, a study published Wednesday by the journal Neurology found.
Exposure to formaldehyde, a strong-smelling gas used in manufacturing wood and chemical products, plastics and in other applications, increased the risk for thinking and memory problems by 17%, the data showed.
Workers exposed to formaldehyde for 22 years or longer had a 21% higher risk for cognitive impairment compared to those who never were in environments with the chemical, the researchers said.
Those with the highest cumulative exposure to formaldehyde had, on average, a 19% higher risk of experiencing cognitive impairment compared to those who had not been exposed, researchers said.
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However, the findings do not prove that exposure to formaldehyde causes cognitive impairment, but rather that there is an association between the two, they emphasized.
"We know that exposure to formaldehyde has been linked to certain cancers, and our results suggest that exposure to low amounts of formaldehyde also may be associated with lower level of cognitive functioning," study co-author Noemie Letellier said in a press release.
"People whose work exposes them to formaldehyde may want to take precautions, and companies may want to look at ways to reduce workers' exposure to the hazardous chemical," said Letellier, an epidemiologist at University of Montpellier in France.
Earlier studies have linked formaldehyde exposure with neurological diseases, such as amyotrophic lateral sclerosis, or ALS.
In addition, previous research by Letellier and her colleagues found that poor air quality is linked with increased risk for dementia.
For this study, the researchers assessed the cognitive function of 75,322 adults in France with an average age of 58 by using seven common tests of word recall, memory, attention, reasoning and other thinking skills.
Of the study participants, 8%, or just over 6,000, were exposed to formaldehyde during their working life, the researchers said.
The occupations of those exposed included nurses, caregivers, medical technicians, workers in the textile, chemistry and metal industries and carpenters and cleaners, according to the researchers.
The maximum possible score on the cognitive tests was 135. The group not exposed to formaldehyde had an average score of 66, while those exposed to the chemical had an average score of 63, the data showed.
"The use of formaldehyde has decreased over the last few decades," Letellier said.
"However, our results highlight the fact that there are still thousands of people whose work exposes them to the chemical, and they may face the risk of cognitive impairment later because of it," she said.