Australasian Science: Australia's authority on science since 1938

Traffic Shortens Pregnancies

By Stephen Luntz

Women living close to freeways or major roads during pregnancy are more likely to give birth prematurely, according to a study at the Queensland Institute of Technology’s Institute of Health and Biomedical Innovation.

“The most striking result was the reduction in gestation time of 4.4%, or almost 2 weeks, associated with an increase in freeways within 400 metres of the women’s home,” says Prof Adrian Barnett.

“Although the increased risks are relatively small, the public health implications are large because everyone living in an urban area gets exposed to air pollution. Pre-term and low-birthweight babies stay in hospital longer after birth, have an increased risk of death and are more likely to develop disabilities.”

Barnett also points to a Swedish study that found pre-term babies are also less likely to attend university or have high-paying jobs, after allowing for parental socio-economic status.

Barnett’s research, published in Environmental Health, was based on 970 mothers in Logan City, an area south of Brisbane that includes semi-rural areas as well as locations surrounded by busy roads. He says his sample could not distinguish between air pollution and noise as a cause, but says other research indicates that traffic fumes are more likely to be responsible. “People living high up in apartments might still be exposed to noise, but the air pollution probably doesn’t get up there.”

Pollution exposure can happen outside the home as well, and Barnett says he is corresponding with a Spanish team that did similar work but focused on women who spent most of their time at home. “The more accurate measure of exposure you get, the stronger association is found,” Barnett says.

Barnett prefers to stay away from using arbitrary dates, such as whether babies were born before or after 37 weeks, saying: “The evidence is that every extra week you spend in the womb is good.”