Impairment from solvents might last decades
May 12th, 2014
04:00 PM ET

Impairment from solvents might last decades

In the workplace, fumes from solvents such as paints, glues, degreasers and adhesives have been implicated in cognitive damage - in other words, impaired thinking and memory abilities. Now, researchers report in the journal Neurology that the detriments linked to these chemicals might last many years.

"What it shows is that these chemicals might have more long-term effects than have previously been thought, and continue to affect people long after they are retired," said Erika Sabbath, research fellow at the Harvard Center for Population and Development Studies and lead author of the study.

A solvent is a substance used to dissolve another chemical. For instance, water dissolves salt. The solvents targeted in this study included benzene (found in detergents and plastics), chlorinated solvents (found in paint strippers and dry cleaning solutions) and petroleum solvents (found in varnish).

But note that researchers did not directly measure whether these chemicals cause brain damage. They simply found a statistical association between impairment on tests and exposure to chemicals. More research would be needed to prove that one directly results in the other.


Researchers obtained information from 2,143 male retirees in France who had worked for a French utility company. They had retired, on average, around age 55. Most had started working around their late teens or early 20s and worked at the same company for their whole careers.

About 33% of these retirees had been exposed to chlorinated solvents, 26% to benzene and 25% to petroleum solvents. There were 12% of participants with high exposure to one kind of solvent, while 11% had high exposure to two or three.

Those exposed to industrial solvents 12 to 30 years before cognitive testing were deemed to have been "recently" exposed. Others had been exposed 31 to 50 years earlier.


Researchers estimated how much people had been exposed each year from 1960 to 1998. The study did not directly measure how long individuals had been exposed to certain chemicals, however.

"During that time, the practices around using chemicals and personal protective equipment and the extent to which we know about harmful effects have certainly changed," Sabbath said. "It's possible that these people were exposed to higher levels than what people are exposed to today. That being said, these are some of the most common chemicals in U.S. workplaces."

Study authors gave participants cognitive tests to measure such abilities as working memory, attention and thinking skills. The men were on average 66 at the time of this testing.


Participants whose exposure to solvents was greater and most recent had the highest risk of memory and thinking problems.

High exposure to chlorinated solvents, petroleum solvents and benzene during one's lifetime was linked to impairment on a test measuring general cognitive function. For those with moderate exposure, only chlorinated solvents was related to higher risk.

A different cognitive test found similar results, with high exposure to chlorinated solvents and petroleum solvents related to elevated risk. Other assessments found similar patterns.

Timing mattered, too. Poorer scores on tests that measured visual attention and memory, as well as task switching, were more likely to be seen in men whose exposure to chlorinated solvents was both high and recent. Researchers looked at other factors such as smoking, age, education and alcohol consumption, but none of these explanations could account for the strong association.

High exposures 31 to 50 years before testing were also associated with some types of cognitive impairment.

"We expecting to see this relationship between total lifetime dose and cognitive outcomes, but we weren’t expecting that the effects would have lasted this long," Sabbath said.


Researchers did not test the cognitive functioning of participants before their exposure to solvents.

"This could potentially induce bias if individuals with poorer baseline cognition were more likely to stay in higher-exposure jobs, incurring additional damage from solvents," researchers wrote.

The participants also took a variety of different tests, and some results may be explained by random chance.

Researchers additionally did not take into account factors such as physical activity, diet and cardiovascular disease. But they did adjust for hypertension and body mass index, which are related.


This study did not look at what happens to the brain directly as a result of solvent exposure in the workplace. But a previous study that used functional magnetic resonance imaging found implications to the anterior cingulate cortex, dorsolateral prefrontal cortex and prefrontal cortex while participants took attention and working memory tests. Researchers noted that deterioration of the prefrontal cortex is also associated with aging.

Solvents are used in nearly all manual tasks in the French working population, with 12% to 13% being exposed, the study said.

Policy changes may be necessary to reduce the level of chemical exposure that is permissible, but historically such reforms have been difficult to achieve, Sabbath said.

In the meantime, people who work with paints or dry cleaning fluid all day may benefit from wearing a respirator and having good ventilation, Sabbath said.

"There’s absolutely nothing to be lost by prevention," Sabbath said.

soundoff (13 Responses)
  1. Steve

    So industrial solvents and other VOCs are bad for you.... who would have thought.....

    May 22, 2014 at 00:25 | Report abuse | Reply
  2. Frank

    Hi Kevin � I agree with your last point. However, it is just a fact that the grading you refer to is very often regarded as and communicated as a lesson observation grade

    May 25, 2014 at 14:59 | Report abuse | Reply
  3. jmadeo

    The article is summed up very well ""There’s absolutely nothing to be lost by prevention". If there is a question as to whether or not a compound is dangerous, then we should be having our employees wear respirators while working with these products. Spending money up front on prevention can save companies in the long run.

    May 28, 2014 at 11:31 | Report abuse | Reply
  4. Fred Sarver

    I have been exposed , after being a profewsional painter for 22 years.
    My mailing address is- 1460 pine street Clearwater fl 33756, Thankyou for your concerns and time

    August 7, 2016 at 18:35 | Report abuse | Reply
  5. Bradly Bremme

    logiciel de facturation


    September 10, 2016 at 15:42 | Report abuse | Reply
  6. Paddle app

    It's just like a diet you are what you eat you are what you surround yourself in. Looking at a computer screen for your entire life will damage your eyesight.

    June 14, 2017 at 14:26 | Report abuse | Reply
  7. Octavio Nicolette

    Someone necessarily assist to make significantly articles I might state. That is the very first time I frequented your website page and so far? I amazed with the analysis you made to make this actual submit amazing. Great process!


    January 10, 2021 at 23:29 | Report abuse | Reply
  8. Keely Dragt

    To be sure with all your thoughts here and I love your blog! I’ve bookmarked it to ensure that I am able to come back & read more in the future.


    January 11, 2021 at 23:28 | Report abuse | Reply
  9. Dorla Treff

    You really make it seem really easy with your presentation but I to find this topic to be actually something that I believe I might never understand. It kind of feels too complex and very vast for me. I'm looking ahead in your next post, I¡¦ll attempt to get the cling of it!


    January 17, 2021 at 23:47 | Report abuse | Reply
  10. Marquetta Lathan

    Thanks so much for providing individuals with an extraordinarily special chance to discover important secrets from this website. It can be so pleasant plus packed with a good time for me personally and my office colleagues to search your website at least three times weekly to learn the fresh items you have got. And lastly, I'm also certainly satisfied with your excellent tricks you give. Some 3 ideas on this page are unquestionably the most efficient I've had.


    January 21, 2021 at 03:37 | Report abuse | Reply
  11. Eddy Freels

    Nice blog right here! Additionally your web site lots up very fast! What host are you the usage of? Can I am getting your affiliate link in your host? I wish my site loaded up as fast as yours lol


    January 28, 2021 at 22:00 | Report abuse | Reply
  12. ClarkTauts

    y6bxh gb5nq h6q3

    March 2, 2021 at 01:02 | Report abuse | Reply
  13. โกง

    271515 452412Id need to verify with you here. Which isnt something I often do! I take pleasure in reading a post that may possibly make folks think. Additionally, thanks for permitting me to comment! 875092

    March 19, 2021 at 14:22 | Report abuse | Reply

Post a comment


CNN welcomes a lively and courteous discussion as long as you follow the Rules of Conduct set forth in our Terms of Service. Comments are not pre-screened before they post. You agree that anything you post may be used, along with your name and profile picture, in accordance with our Privacy Policy and the license you have granted pursuant to our Terms of Service.

About this blog

Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.