Chlorine from water and salt during
cooking could create toxic molecules
Chlorination of tap water brought a revolution
in the prevention of infectious diseases. At the waterworks either chlorine or
hypochlorites are added to the water, or for the disinfection chlorine and
ammonia is used which react together to create chloramine. Chlorine is highly
reactive and disrupts vital organic molecules in cells. Thus they reliably
exterminate all germs which got into the water.
The reaction of chlorine with other substances
present in the water is a varied range of compounds that are still only
partially explored. Their effects on the human body is the big unknown. Chinese
scientists published in the scientific journal Water Research the results of analysis of substances formed during
cooking of food in the chlorinated water.
Scientists warmed chlorinated water blended with wheat flour and iodized table salt. Iodine from the salt is reacted with chlorine
from the water on hypoiodous acid.
This in itself isn't cause for concern, but the acid can then react with the food and other organic matter in the tap water to create cooking iodinated disinfection byproducts (I-DBPs) - molecules that are almost completely new to researchers. For the new study, the team identified some molecules and tested their toxicity.
Some of the substances formed during the cooking of food in chlorinated water are apparently harmless. Others however have toxic effects.
"Considering that
these molecules could have an adverse effect on our health, we need to study
them more to determine exactly what effects they might have," said Dr. Yang Pan, one
of the study's authors and Assistant Professor at Nanjing University.
The results show that the formation of potentially hazardous
substances can significantly reduce the cooking conditions. It is generally
recommended to cook at lower temperatures, thus avoiding these effects e.g.
cooking by using pressure cookers, and cooking for shorter periods. The risk of
potentially toxic substances is lower in the disinfected water with chlorine or
hypochlorites in comparison with chloramine disinfection. It depends also on
the form in which iodine is added to table salt. There is a lower risk of toxic
substances when using salt with the addition of potassium iodate than the salt,
wherein iodine is supplemented in the form of potassium iodide.
It might help add salt
after the meal is cooked or get some good quality home water filter.
More
information: Yang
Pan et al. Identification, toxicity and control of iodinated disinfection
byproducts in cooking with simulated chlor(am)inated tap water and iodized
table salt, Water Research (2016). DOI: 10.1016/j.watres.2015.10.002