Does cigarette smoke contaminate tap water?
A group of water industry pros and academics recently set out to answer that question. The group included the Metropolitan Water District of Southern California and researchers from the University of Alberta.
They published their findings Environmental Science & Technology in a paper titled "Identification of Tobacco-Specific Nitrosamines as Disinfection Byproducts (DBPs) in Chloraminated Water."
"Here we report on the investigation and evidence of TSNAs as a new class of disinfection byproducts," the study said.
Their theory was "that the so-called tobacco-specific nitrosamines (TSNAs) might be found in water. They are present in tobacco smoke and are known to be carcinogenic. They could emerge in smokers’ urine to contaminate water supplies, or might also be found in water following their formation during the disinfection process," according to Spectroscopynow.
The researchers tested treated water from seven drinking water treatment plants and two wastewater treatment plants. They tested for five tobacco-specific nitrosamines (TSNAs), including (methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). Their method allowed them to register TSNAs at levels as low as 0.02 ng/L.
They took treated water from the plants "and treated it with ammonia then chlorine to simulate conditions during water disinfection," the Spectroscopynow said.
"The detection of NNAL and NNN in the samples after the treatment, but not before, confirmed that they are DBPs. NNK was present before treatment but was found at much increased levels afterwards, so it can be regarded both as a DBP and a wastewater contaminant. These tests illustrated that the precursors of TSNAs are present in wastewater and have the potential to be converted," Spectroscopynow said.
The researchers then tried a closer examination.
"They found that the raw water from the positive effluent had a relatively high ammonia content, so much so that the added chlorine was insufficient to destroy NDMA and other TSNA precursors. However, even the total amount of NNK and NNAL in this effluent, at 0.3 ng/L, was about 200-fold lower than the amount of NDMA. This compares with a reported 10–6 cancer risk of 0.8 ng/L for TSNAs and 0.7 ng/L for NDMA,' the report said.
These researchers are not the first to investigate how cigarettes affect the water supply. The anti-smoking lobby has long explored the connection.
American Legacy Foundation, an anti-smoking group, says cigarettes are harmful to water. "Cigarette butts are the number one littered item on US beaches and roadways. They leach chemicals that are poisonous to wildlife and can contaminate water sources," the group says.
For more, check out Water Online's Drinking Water Disinfection Solution Center.
Image credit: "Cigarette," © 2011 Fried Dough, used under an Attribution 2.0 Generic license: http://creativecommons.org/licenses/by/2.0/deed.en
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