Malathion sprayed across Winnipeg in June may not have met World Health Organization (WHO) guidelines, according to an analysis of lab results. Toxic isomalathion levels can increase in the chemical with time or when exposed to heat. An analysis of lab test results revealed that a 2,000-litre batch of malathion from 2007 obtained from the province does not meet WHO guidelines because of elevated levels of isomalathion. The cut off for isomalathion concentrations in any given malathion batch is 0.4 per cent. The city says it is currently in discussions with the province to return the unusable 2007 malathion.

Source: CBC News August 22, 2016 22:52 UTC