Research progress on effects of PM2.5 exposure during pregnancy on maternal and infant thyroid function / 环境与职业医学

Ambient air pollution has become a widespread global public health problem. As one of the main components of ambient air pollution, fine particulate matter (PM2.5), with its small diameter and large surface area, can carry a variety of toxic substances and enter the blood circulation directly through the blood-air barrier, damaging various tissues and organs of human body. Studies have shown that PM2.5 exposure during pregnancy can disrupt the mother's and child's thyroid function. Since the fetal thyroid gland does not begin to develop until around the sixth week of pregnancy, the fetal thyroid hormone is almost entirely dependent on the mother during early stages of pregnancy, and maternal thyroid hormone level play a crucial role in the growth and development of fetus. When a mother is exposed to PM2.5 during pregnancy, placenta, the "bridge" between mother and fetus, is also affected to some extent, including changes in placental iodine uptake and oxidative stress, inflammation, and DNA methylation in placental tissue. Exposure to PM2.5 during pregnancy also alters maternal thyroid hormone level and normal placental function, which can have a detrimental effect on pregnancy outcomes, such as preterm birth, low birth weight, and neurological abnormalities. This paper reviewed the effects of PM2.5 exposure during different trimesters on maternal and infant thyroid function, placental function, and pregnancy outcomes, aiming to provide more accurate protection of maternal and fetal health.

Developmental toxicity of exposure to ambient fine particulate matter / 上海交通大学学报（医学版）

Domestic and foreign studies have shown that fine particulate matter (PM2.5) pollution is a major factor affecting human health. In addition to the direct impact on the respiratory and cardiovascular systems, PM2.5 exposure during pregnancy can directly affect the growth and development of offspring, manifested as cardiopulmonary dysfunction and cognitive disorder, various adverse pregnancy outcomes, abnormal organ development, and congenital defects. However, the mechanism underlying the developmental toxicity of PM2.5 is still unclear. This article reviews PM2.5-induced developmental toxicity based on epidemiological investigation and toxicological studies, which will provide references for further studies.