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Thirdhand smoke can damage liver, brain tissues: study

Press Trust of India  |  Los Angeles 

Exposure to thirdhand-smoke can significantly harm your liver and brain tissues within a month - with the effect worsening over time, scientists have warned.

Thirdhand-smoke (THS) when exhaled smoke and smoke emanating from the tip of burning cigarettes gets on surfaces such as clothing, hair, homes, and cars.


THS can cause hyperactivity, liver and lung damage, type 2 diabetes and wound-healing complications in mice.

Researchers investigated the effects of THS exposure on biological molecular markers - or "biomarkers" - found in serum, and in liver and brain tissues.

"Our goal was to determine the minimum amount of time required to cause physiological changes in mice when they are exposed to THS, using an exposure system that mimics human exposure," said Manuela Martins-Green, professor at University of California, Riverside in the US.

"We found that THS exposure as early as one month resulted in liver damage. THS exposure for two months resulted in further molecular damage, and at four to six months caused even more such damage," said Martins-Green.

"We also found that the mice showed insulin resistance after long-term THS exposure," she said.

Damage to the liver can hinder its capability to detoxify the body, leading to more damage by THS toxins. Researchers examined the brains of THS-exposed mice and found that stress hormones, such as epinephrine, increased in one month of exposure.

Additional stress hormones are seen at two months, four months, and six months, eventually causing immune fatigue in the mice.

"THS is a stealth toxin, a silent killer. Contaminants can be absorbed through the skin and through breathing," Martins-Green said.

Most people are either unaware they are being exposed to THS, or do not believe in the damage THS can do, she said.

THS toxins, which are invisible but can be smelled, remain on surfaces for many years, and are resistant to even strong cleaning agents.

Further, they accumulate and age by reacting with the ambient air, and change into carcinogenic chemicals.

Since THS is absorbed through skin, children are especially vulnerable given their close contact with household surfaces. Children frequently ingest these toxins by putting their hands in their mouths.

They also absorb them through the skin. Children living in the homes where smoking has occurred have been known to show tobacco metabolites in their urine as well as tobacco- derived carcinogens called tobacco specific nitrosamines.

Researchers exposed mice to THS for up to six months, collecting brain, liver, and serum samples after one, two, four, and six months of exposure to test for hormonal alterations, insulin resistance, metabolic syndrome, and damage to the liver and brain.

"We found a positive time-dependent significant correlation with increased time of THS exposure and the effects it had on all the variables we measured," Martins- Green said.

"These biomarkers, once validated in humans, can be used as critical indicators of exposure to THS, and how long this exposure has occurred," she said.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)

First Published: Sun, September 17 2017. 17:32 IST
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