Few developments have eroded trust in the Communist Party as quickly as the realization that the leaders have failed to rein in threats to children’s health and safety. There was national outrage in 2008 after more than 5,000 children were killed when their schools collapsed in an earthquake, and hundreds of thousands were sickened and six infants died in a tainted-formula scandal. Officials tried to suppress angry parents, sometimes by force or with payoffs.

But the fury over air pollution is much more widespread and is just beginning to gain momentum.

“I don’t trust the pollution measurements of the Beijing government,” said Ms. Zhang’s father, Zhang Xiaochuan, a retired newspaper administrator.

Scientific studies justify fears of long-term damage to children and fetuses. A study published by The New England Journal of Medicine showed that children exposed to high levels of air pollution can suffer permanent lung damage. The research was done in the 1990s in Los Angeles, where levels of pollution were much lower than those in Chinese cities today.

A study by California researchers published last month suggested a link between autism in children and the exposure of pregnant women to traffic-related air pollution. Columbia University researchers, in a study done in New York, found that prenatal exposure to air pollutants could result in children with anxiety, depression and attention-span problems. Some of the same researchers found in an earlier study that children in Chongqing, China, who had prenatal exposure to high levels of air pollutants from a coal-fired plant were born with smaller head circumferences, showed slower growth and performed less well on cognitive development tests at age 2. The shutdown of the plant resulted in children born with fewer difficulties.

Analyses show little relief ahead if China does not change growth policies and strengthen environmental regulation. A Deutsche Bank report released in February said the current trends of coal use and automobile emissions meant air pollution was expected to worsen by an additional 70 percent by 2025.

Some children’s hospitals in northern China reported a large number of patients with respiratory illnesses this winter, when the air pollution soared. During one bad week in January, Beijing Children’s Hospital admitted up to 9,000 patients a day for emergency visits, half of them for respiratory problems, according to a report by Xinhua, the state news agency.