While 42 states require public school students to take a sexual education course that covers at least one topic within this subject between kindergarten and high school, only 19 states mandate that this instruction be medically accurate—and 5 of those states only require medical accuracy for specific topics, according to a new study in the American Journal of Public Health. The study also found that 34 states that mandate sexual education in public schools require instruction on abstinence, a method that has consistently proven to be ineffective or harmful to adolescent sexual health, but continues to be embraced and funded by the federal government. Thirty-four states also allow parents to opt their children out of receiving any sexual education instruction, while five states require parents to opt in for their children to receive this instruction. 

New research from the City University of New York suggests that the combined effect of summer heat and urban air pollution may trigger hormonal changes in children, with long term consequences on their behavioral development.