Who conducted the study?

Farshid Soleimani, from the Hormozgan University of Medical Sciences in Iran, and Mohammad Reza Masjedi, from the Iranian Anti-Tobacco Association’s Tobacco Control Research Center, led the study. Additional researchers were from the Iran University of Medical Sciences, Bushehr University of Medical Sciences, and the University of Duisburg-Essen in Germany.

When did they do it?

This study was published in December 2023.

Where did they do it?

Data was collected in 79 cafés in Bushehr, a port city along the Persian Gulf in Iran.

How did they do it?

The researchers collected dust samples in 35 waterpipe (or hookah) cafés, 19 cigarette cafés, and 25 smokefree cafés. They also took notes on the apparent ventilation, number of windows and doors, size of the room, and the number of people smoking in each café. Back in the laboratory, the researchers analyzed the type and amount of primary aromatic amines (PAAs) in each dust sample. PPAs are toxic substances in thirdhand smoke derived from ammonia and contribute to the chemical residue left behind when people smoke tobacco. The researchers also estimated how much PAAs infants, toddlers, children, teenagers, and adults would be exposed to if they visited each café.

What did they find?

The researchers found that dust in waterpipe cafés had the most PAAs. This was followed by dust in cigarette cafés. Smokefree cafés had the least amount of PAAs. The more ventilation, windows and doors, or space a café had, the less PAA’s the researchers detected. The researchers found that toddlers would be exposed to the most PAAs when visiting these cafés, which matches many other studies that have found that young children are the most likely to be exposed to thirdhand smoke residue.

Why is this study important?

This study confirms that waterpipes generate PAAs that collect as thirdhand smoke residue in dust. The study even found that waterpipe cafés had more thirdhand smoke in dust than cigarette cafés. Thirdhand smoke in dust is hazardous to everyone, especially young children.  The findings highlight a need to protect young children from indoor environments in which people smoke cigarettes or waterpipes. The results of this study can be used to inform people that avoiding waterpipe and cigarette cafés can help prevent exposure to toxic thirdhand smoke.

Click here to read the research study.