increased only when hosts were exposed to an atrazine concentration of 30 mg/L and not to 3 mg/L. A 2008 study reported that tadpoles developed deformed hearts and impaired kidneys and digestive systems when chronically exposed to atrazine concentrations of 10 ppm in their early stages of life. Tissue malformation may have been induced by ectopic programmed cell death, although a mechanism was not identified. In 2010, the Australian Pesticides and Veterinary Medicines Authority (APVMA) tentatively concluded that environmental atrazine "at existing levels of exposure" was not affecting amphibian populations in Australia consistent with the 2007 EPA findings. APVMA responded to Hayes' 2010 published paper, that his findings "do not provide sufficient evidence to justify a reconsideration of current regulations which are based on a very extensive dataset." A 2015 EPA article discussed the Hayes/Syngenta conflict to illustrate both financial and nonfinancial conflicts of interest. The authors concluded, "Statements by Hayes and Syngenta suggest that their scientific differences have developed a personal aspect that casts doubt on their scientific objectivity". 2012 Class action lawsuit In 2012, Syngenta, manufacturer of atrazine, was the defendant in a class-action lawsuit concerning the levels of atrazine in human water supplies. Syngenta agreed to pay $105 million to reimburse more than one thousand water systems for "the cost of filtering atrazine from drinking water". The company denied all wrongdoing. 2015 Canadian regulatory review Prompted by the EU's 2004 ban, a regulatory review of the product in Canada by the PMRA was begun in 2015. On 31 March 2017 the review result was published and the PMRA decided to leave unchanged the product's registration. This was done because while the EU's ban was based on a legislated pollutant level of 0.1 μg/L, the Canadian regulations call for a home-grown "risk-based scientific approach in determining the risk to human health from pesticides in drinking water." The US drinking water standard of 3 μg/L is approximately the same to the Canadian standard of 5 μg/L. Both maximum pollutant levels in North America were not exceeded by the maximum pollutant level in Canadian data of 2.32 μg/L. See also Pesticides in the United States – Atrazine Endocrine disruptor Simazine References External links Atrazine- PubChem(National library of medicine) - atrazine Atrazine Fact Sheet - National Pesticide Information Center - Atrazine Fact Sheet Atrazine - CDC - NIOSH Pocket Guide to Chemical Hazards Endocrine disruptors GPER agonists Herbicides Triazines Chloroarenes Suspected