A total of 1,665 Connecticut children under age 6 had lead poisoning in 2017, a drop of almost 17% from the year before and the largest one-year decrease in five years, according to a just-released report from the state Department of Public Health (DPH). But more children showed higher levels of the toxin in their blood than in 2016, the report says. In 2016, there were 105 children whose blood lead level was 20 micrograms per deciliter of blood or higher, at least four times the measure at which they’re considered poisoned. In 2017, the number had risen to 120 children. DPH epidemiologist Tsui-Min Hung said the improved overall numbers were at least partially due to the department’s more aggressive prevention activities, which 42 local health departments took advantage of, as well a social media campaign.