News
Thursday, May27th, 2010
Inmaculada Aguilera: "Pollution affects the health of the fetus"
Inmaculada Aguilera, a graduate in Environmental Sciences. Postgraduate Diploma in Epidemiology and Clinical Research, answered the ten questions you have raised. Inma stresses that the effect of contamination of the fetus begins to be observed at mid-pregnancy and throws the following message: "the study's findings should be taken into account in the implementation of more stringent environmental policies."
Why all the studies focus between weeks 20 and 32 of the management?
Weeks 12, 20 and 32 of pregnancy are about three times of pregnancy on ultrasound scans are performed for antenatal care of pregnant women in the health system. Therefore we evaluated the growth of the fetus between weeks 12 to 20 and between 20 and 32 weeks. We have also calculated the exposure to air pollution in these same periods, to investigate whether a relationship exists between fetal growth in a given time and exposure to contamination prior to that time.
What difference in weight in the fetus could be between a woman from a rural and an urban area?
The cohort of Sabadell is exclusively urban, so we compared women living in areas with different pollution levels within the same city. It will be interesting to see the results of other cohorts, such as Valencia and Asturias, which does combine urban and rural areas. While certainly the pollution levels are higher in urban than in rural areas, there are other factors that differentiate these areas and they have to be taken into account when considering the relationship between pollution and fetal growth, such as socioeconomic variables.
Which is why just have found evidence that the pollution affected the fetus in the period between weeks 20 and 32.
Hard to say, as yet unknown the exact biological mechanisms through which pollution affect fetal growth. Our study is consistent with two previous studies, the only who have used ultrasound, that the effect on the fetus begins to be observed at mid-pregnancy.This may help us in the hypothesis -as, for example, an alteration in the growth of the placenta, which would entail a lower supply of nutrients and oxygen to the fetus-, but experimental studies are needed to further investigate these biological mechanisms.
If you had to highlight some aspect of the study, which would you choose?
To me, the most important is that differences in pollution levels within a city have an effect on fetal health. It's something that has also been observed for other health effects such as respiratory or cardiovascular disease. Therefore, the fact of living in one area or another within the same city appear to affect the health of their inhabitants.
"The differences in the levels of pollution within a city have an effect on fetal health"
What future do you think lessons would be learned from the study data?
Given that pregnant women and fetuses are most vulnerable populations, the results of this stud y-and others also indicate a lower fetal growth associated with pollution- should be taken into account in the implementation of more stringent environmental policies . A locally should also be taken into account pollution levels in urban approach, when to place facilities associated with the children, as colleges and nurseries.
The study speaks only of urban traffic pollution, do you think that other types of pollution such as industrial, might have similar effects?
In this study we measured exposure to nitrogen dioxide (NO2) and volatile organic compounds (VOCs) and used as indicators of pollution from traffic, but can also be related to industrial emissions, particularly VOCs. Although industrial emissions can be very important in specific areas, in the case of Sabadell, and in most european cities, the most important source of pollution is traffic. However, we do not know if the observed effects are due in particular to these contaminants or to other equally emitted by vehicles.
In the study commented that the negative effect of pollution on the fetus is small, but he also noted some of the possible consequences of this pollution, such as neurodevelopmental delay, impaired growth ...
It is true that we have found the effect of pollution on fetal growth is small, but since the population is exposed to air pollution, and that intrauterine growth retardation is quite common in the general population, the impact on health of an entire population can be significant. Intrauterine growth retardation may have consequences in the child -development disorders- as in the adult: cardiovasaculares disease development and metabolic syndrome. In this context, exposure to air pollution has to be understood as one factor, but certainly not the principal, that a child may influence fetal growth.
Had he performed before a similar study? Do you plan any more in the future?
We are conducting a joint analysis of the four cohorts de novo (Valencia, Sabadell, Asturias, Guipúzcoa) to study the effect of pollution on the weight, height and head circumference at birth. Subsequently analyzed data from the scans in all four cohorts, so we will have a larger population sample with more variability in exposure. In addition, we are also interested in studying the effect of pollution on preterm birth.
"The design of a city affects many factors related to exposure to air pollution"
What steps can be taken about the circumstances alleged?
One of the problems of air pollutants is that it is difficult to avoid exposure as it is strongly determined by where we live. It is therefore very important to the performance of local governments, since the design of a city influences many factors related to exposure to air pollution from emissions to the amount of physical activity of its inhabitants.
Knowing the passive agents who are affected by this pollution, particular type of the fetus or child is more likely to be more contaminated than another?
Studies show that diet, specifically the intake of antioxidant nutrients, may attenuate the negative effect of pollution on fetal development. On the other hand, it seems that some people are more susceptible to the effects of pollution from a genetic standpoint. In this study we have not evaluated and the role of diet during pregnancy and genetic susceptibility to the effects of pollution, but it's something we plan to do in the near future.
Universe of the study: of the 657 women belonging to the cohort of Sabadell INMA Project were selected which had at least two ultrasounds during pregnancy, who lived in Sabadell throughout pregnancy and giving birth in hospital Parc Taulí. In total, 562.