A child’s blood pressure may be shaped, in part, before they even take their first breath.A new study finds exposure to fine particle air pollution during pregnancy and early childhood is linked to higher blood pressure by school-age.Fine particles are tiny pollutants in smog that can travel deep into the body.Even at relatively low levels, early exposure to this type of pollution may affect kids’ long-term heart health, researchers warn.Their study included more than 4,800 children whose blood pressure between ages 5 and 12 was compared to air pollution exposure during pregnancy and the first two years of life.Kids exposed to higher pollution levels before and after birth had higher average blood pressure.Exposure during the first trimester showed the strongest link, particularly with higher systolic blood pressure — the top number in a reading.One surprise, exposure to nitrogen dioxide, particularly later in pregnancy, was associated with slightly lower blood pressure in children — a finding researchers say needs more study.The authors say these findings are especially concerning as high blood pressure in children has risen nearly 80% over the past two decades.Source: Environmental Research.Sign up for our weekly HealthDay newsletter