LYNN – Starting Tuesday, weekday afternoons in many of the city’s neighborhoods will be a bit more congested again as parents will begin infiltrating school yards and the surrounding streets while picking up their children from school.While enrollment is up at many of the city schools, meaning more parents waiting in line for dismissal, the sound of engines will be quiet and the air a bit cleaner thanks to a new Massachusetts law aimed to put an end to vehicle idling.Parents and bus drivers waiting to pick up their children from school will risk being hit with a $100 fine this year if they allow their vehicles to run idle while they queue up in front of the school.The anti-idling regulations, which apply to every vehicle on school grounds and took effect Aug. 21, are part of an effort by the Registry of Motor Vehicles to increase safety and decrease harmful automobile emissions near schools.”We know that an idling engine releases twice as much exhaust as a moving vehicle,” said Registrar Rachel Kaprielian. “Turning off your vehicle engine may save a child from the harmful exposure of engine exhaust.”According to the American Lung Association (ALA), children are particularly vulnerable to the effects of exhaust because their lungs are not fully developed and they breathe twice as much air as adults. Between familyvehicles, which can range from small vehicles to large SUVs, and school buses and DPW trucks that are decidedly less fuel-efficient than smaller cars, children in school yards are exposed to heavy amounts of air pollution each day.”The American Lung Association was a strong advocate for these regulations,” said Brian Simonds, chairman of the Massachusetts leadership board of ALA. “Not only do we urge parents and school personnel to obey the law on school grounds, but we hope they practice idle-free behavior everywhere. We know that healthy air means healthy lungs.”According to the RMV, 9,000 school buses transport nearly 750,000 children to and from school daily in Massachusetts, although the majority of students in Lynn are transported by their parents or public transportation.The new law is expected to have a significant impact on lung health in Massachusetts. Approximately 11 percent of Massachusetts children suffer from asthma compared to the national average of eight percent, according to the ALA.Kaprielian said there are additional benefits to the new law.”It will help reduce air pollution and health care costs as well as save school districts and motorists fuel, money and wear and tear on buses and vehicles.”The Lynn Police will be responsible for enforcing the new law, which comes with a $100 fine for a first offense and a $500 fine for additional offenses.