Despite such limitations to studying these effects, “we are getting more and more consistent signals that particles are related to these birth outcomes and they may affect prenatal development,” says Beate Ritz, an environmental epidemiologist at the University of California, Los Angeles. She has studied the connection between particulate matter and birth weight in California since the 1990s, but was not involved in the latest analysis.

Epidemiologists are concerned that some of the effects of a mother's exposure to air pollution may not be seen until several decades after her children are born. “If you think of what is happening in China, that doesn’t bode very well,” says Ritz, referring to recent reports of dangerous air-pollution levels in some Chinese cities. For example, in late January, the 24-hour average reading for PM_2.5 in Beijing reached more than 460 μg m^–3 according to the US Embassy there; China’s Ministry of Environmental Protection reported a lower figure of around 350 μg m^–3.

The World Health Organization recommends that countries establish rigorous air-pollution standards of an annual mean of 10 μg m^–3 for PM_2.5 and 20 μg m^–3 for PM₁₀. The US Environmental Protection Agency recently strengthened its annual PM2.5 standard by decreasing it from 15 μg m^–3 to 12 μg m^–3. The agency estimates that meeting this standard will provide health benefits worth between US$4 billion and $9.1 billion annually by 2020.

“The impacts of air pollution on pregnancy have not been considered when setting up the regulations,” says Dadvand. “Now is the time to start thinking about it.”

This article is reproduced with permission from the magazine Nature. The article was first published on February 6, 2013.

6 Comments

1. 1. tierra7 07:19 AM 2/7/13

   Dear friends: The Urban Air pollution continue as we use fossil fuels, or about 180 years ..! It is essential to clean the interior and urban air now ..! Breathing clean air preserves the health of people.!! Here in Peru and we are clearing the air with our Super Tree with excellent results: www.tierranuestrape.org
   Thanks and I hope this helps in some
   Jorge

   Reply | Report Abuse | Link to this

2. 2. KSama 02:30 PM 2/7/13

   Pollution causes lack of oxygen / hypoxia and therefore increased red blood cells , to attempt to oxygenate the blood , and increased viscosity of the blood accompanies increased hemoglobin.
   "Elevation of hemoglobin concentration through exposure to indoor air pollution"
   
   The question then might be , does higher hemoglobin or increased viscosity of the blood , lead to lower birth weight ?

   Reply | Report Abuse | Link to this

3. 3. KSama 02:42 PM 2/7/13

   The question then might be , does higher hemoglobin or increased viscosity of the blood , lead to lower birth weight ?
   
   "Risk of preterm birth at high hemoglobin values increased dramatically"
   "There are reports of increased blood viscosity (22)and plasma fibrinogen (related to blood coagulation)(23) during air pollution episodes."

   Reply | Report Abuse | Link to this

4. 4. KSama 03:13 PM 2/7/13

   This states the accepted marker for anemia in women is optimal for birth outcomes , rather than higher hemoglobin as commonly thought.
   "The minimum incidence of low birth weight (<2.5 kg) and of preterm labor (<37 completed weeks) occurs in association with a hemoglobin concentration of 95–105 g/L."
   
   Which agrees with the latest finding in which a hemoglobin below 11 guarantees there is NO preeclampsia.
   "A hemoglobin value below 11.0 g/dL excluded the
   risk for severe preeclampsia to 100%"
   
   Preeclampsia is associated with an increased incidence of low birth weight.
   "More infants were delivered before the onset of labour and by caesarean section in the group with pre-eclampsia. These babies tended to be smaller"

   Reply | Report Abuse | Link to this

5. 5. TonyTrenton 05:33 AM 2/12/13

   Women bare the responsibility for getting pregnant.
   
   Most women consider it is their right to have babies.
   
   Bringing another person into the world. Means that the woman's choice makes her responsible for the actions & suffering of her offspring.
   
   Getting pregnant is a VERY SELFISH act for their own personal satisfaction.
   
   IT IS NOT A RIGHT BUT A RESPONSIBILITY !!!

   Reply | Report Abuse | Link to this

6. 6. bucketofsquid 05:25 PM 2/14/13

   Pollution isn't a modern problem. People have crowded around wood and dung fires for millenia. The particulates in the smoke do all kinds of harm.

   Reply | Report Abuse | Link to this