According to the scientists these are disinfection byproducts that, at this point of the research, still have unknown properties and potential health effects.
Previous studies have shown that the chlorine used to keep swimming pool water sanitary can react with constituents of urine, namely urea, uric acid and amino acids, to produce potentially hazardous disinfection byproducts in swimming pools.
Investigating interaction of chlorine with PPCPs
However, building on this, the team wants its research to demonstrate how pharmaceutical and personal care products (PPCPs), can also interact with chlorine to result in other potentially harmful byproducts.
"The whole motivation for examining pharmaceuticals and personal care products is that there is this unknown potential for them to bring about undesired or unexpected effects in an exposed population," said Ernest Blatchley, a professor with a joint appointment in the Lyles School of Civil Engineering and the Division of Environmental & Ecological Engineering at Purdue University.
"There are literally thousands of chemicals from pharmaceuticals and personal care products that could be getting into swimming pool water."
Research focuses on 32 PPCPs
To drill down on its aims, the research team is tapping into a an analytical technique that identifies and quanifies 32 pharmaceuticals and personal care products in water that has been developed by the Georgia Institute of Technology.
Blatchley says that this method was adapted for its research and used for samples taken from swimming pools across the states of Georgia and Indiana.
The findings, which are detailed in an article published in the December issue of the journal Environmental Science and Technology Letters, shows that of the 32 chemicals investigated, three were detected.
Those chemicals were N-diethyl-m-toluamide, known as DEET, the active ingredient in insect repellants; caffeine; and tri(2-chloroethyl)-phosphate (TCEP), a flame retardant.
"The other 29 could have been present at concentrations below the detection level," Blatchley said.
"And because there are literally thousands of pharmaceuticals, this is just a small subset of compounds that could be present in swimming pools. The main issue is that the release of chemicals into a place like a swimming pool is completely uncontrolled and unknown. I don't want to be an alarmist. We haven't discovered anything that would be cause for alarm right now, but the bottom line is we just don't know."
Future research will be more detailed
For the moment the research is ongoing, with the small sample base throwing up some irregularities that are influenced by the specific locations, specifically that the high readings for DEET were shown in Georgia, a state known for high levels of insects.
The team also conducted controlled experiments on the 32 chemicals in a lab, with very mixed results, ranging from fast to slow reactions and no reaction at all.
The next stage of the research will focus on how the amounts of the chemicals in the study that are used in the various consumer products and then try to correlate that with accumulation in swimming pools.