An investigation of the group of basic and clinical oncology of the ibs.GRANADA shows that pollution affects the weight of the newborn and lung and cognitive development
The A15-BASIC AND CLINICAL ONCOLOGY group is part of a Spanish research group that has followed the growth of 3.700 children (and their mothers) over the past 20 years. The INMA (Childhood and Environment) project originated in follow-up studies that began in 1997 in Ribera d'Ebre and Menorca, and in 2000 in Granada.
These three investigations with volunteers were the basis for launching a much more ambitious program in 2003 with the incorporation of another four studies in Asturias, Guipuzkoa, Valencia and Sabadell (Barcelona).
The Granada participants, no longer so young, have turned 18 and some are studying at our university (UGR). They were invited to participate when their mothers gave birth at the San Cecilio University Hospital between 2000 and 2002, and the study is still ongoing. The many results published to date are making it possible to know the impact of environmental pollution on the development and growth of the participating volunteers.
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When Belén Hinarejos went to have her first pregnancy ultrasound, the one at 2005 weeks' gestation, in 12, a nurse at the San Félix Primary Care Center in Sabadell suggested that she be part of an investigation. This is how the scientific monitoring of the development of her son, Roger, began. Then it was a fetus of only a few grams, but today it is about to turn 15 years old and the tests continue. Both are part of the more than 3.700 mothers and 3.700 children monitored in seven areas of the country within the INMA project coordinated by the Barcelona Institute for Global Health (ISGlobal). An investigation with volunteers that has lasted for 20 years, the largest of its kind in Spain, with results that show the impact of pollution on size at birth, the development of lung or cognitive function.
"I'm a science major, I work as a laboratory technician, and research has always attracted me. I thought I had nothing to lose," says Hinarejos, who, without receiving anything in return, agreed to have blood samples taken and to fill out endless questionnaires about her health, diet, and lifestyle habits. Several of the questions focused on her location: an apartment on a street in Sabadell with heavy traffic and high levels of air pollution. At the same time, pregnancy ultrasounds also began taking measurements of the child she was carrying, such as head size, femur, and weight. Roger was born on May 10, 2006, almost a month before his due date. Despite being a premature baby, he weighed nearly three kilos.
Maite Lemus used to work in a bank, but left to become a teacher. "I was fed up," she says. She also fled the pollution of Valencia and moved to a quiet house on the outskirts of the city, with a terrace overlooking the Mediterranean Sea and the Sierra Calderona mountains. "I was looking for quality of life," emphasizes the Valencian woman, who was recruited for the study in late 2004, when she went to La Fe Hospital for her first pregnancy ultrasound. Her daughter Arantxa was born on June 10, 2005. "Any research that can help health should be supported," emphasizes Lemus, who says that more than 15 years later, she herself has just had her blood taken and a Pap smear performed.
One of the first results obtained with the volunteers' data was that, on average, babies whose mothers lived in areas with more polluted air weighed less and were smaller at birth. This relationship with pollution was even clearer for pregnant women who spent more time at home. Several scientific papers have been published on this subject within the project, such as one published in 2011 in the journal Environmental Health Perspectives, with information from 2.505 mothers and 2.505 babies, including Roger and Arantxa. The researchers estimated the pregnant women's exposure to nitrogen dioxide and benzene and compared the babies' birth measurements. "We discovered that babies born to mothers from more polluted areas weighed on average 70 or 80 grams less than babies born to mothers in less polluted areas," explains Jordi Sunyer, one of the authors of the scientific paper and the first director of the INMA project. "This wasn't due to social differences, because most people in the most polluted areas had better education and more opportunities for a better life," he notes.
At Roger's birth in Sabadell, one of the nurses who collected umbilical cord samples was Silvia Fochs, who later became responsible for his follow-up, along with that of many other children. "We're like their aunts; we've seen them born," she says with emotion. Periodically, usually every two years, they contact the mothers and children to schedule a new visit to conduct more tests and complete more questionnaires. In addition, during this time, they have been collecting all kinds of biological samples, which are stored in freezers at 80 degrees below zero. They are preserved this way so that researchers can access this material as scientific work progresses and because it may be useful in the future to extract important information that is currently unknown. "There is still pregnancy urine from 16 years ago for further research," Fochs emphasizes.
The INMA project's origins lie in studies that began in 1997 in Ribera d'Ebre and Menorca, as well as another launched in 2000 in Granada. These three volunteer studies formed the basis for launching a much more ambitious program between 2001 and 2002, with the addition of four additional follow-up studies (also known as cohort studies) in Asturias, Guipuzcoa, Valencia, and Sabadell (Barcelona). These seven areas, coordinated to harmonize their scientific work, represent a wealth of information for researchers.
In Europe there are even larger studies of this type: if here the babies are already adolescents, in Finland there are still active investigations with people born in the sixties and eighties, and in the UK there are those who follow now to the children of the first children.
If here the babies are already teenagers, in Finland there is still active research with people born in the sixties and eighties, and in the United Kingdom there are now those who follow the children of the first children
At four years of age, one of the tests performed on Roger was a spirometry. This consists of blowing into a device (spirometer) that measures the amount of air that one can retain and the velocity of pulmonary flow. Although this type of test is usually carried out at older ages, the trials with 1.175 children from Sabadell and Gipuzkoa worked and again gave interesting results. The investigation published this time in Thorax in 2015. found a relationship between prenatal exposure to air pollution caused by traffic and impaired lung function in preschool children. "We saw that there was a certain delay in the maturation of these lungs linked to air pollution," emphasizes researcher Jordi Sunyer.
Throughout their childhood, the children were subjected to numerous tests and the systems used to collect the samples were varied. Sometimes, the children were asked to carry backpacks with pollution detectors. Nurses even went to the families' homes to vacuum dust from mattresses or place air meters in windows to analyze the air. "I think I started to become aware of what was happening when I was seven years old. I knew it was an experiment with people my age," says Arantxa. "I've been tested on all kinds of things, but I've always loved it. I feel important and I find it fun."
"I think I started to realize what was happening when I was seven. I knew it was something I should do as an experiment with people my age," says Arantxa. "I've been tested in all sorts of ways, but I've always loved it. I feel important, and I enjoy it."
Last year, Roger had to wear a heart rate watch and a belt that monitored his physical activity and sleep for a while. He also had to carry a sensor to measure pollution in his classroom. "It's true that some of the tests are a bit tedious, but it's for a good cause," says the Sabadell native. "This is very interesting for the future, as pollution has serious consequences for health and the environment."
As detailed by Llúcia González, psychopedagogue at the CIBER (Center for Biomedical Research on the Net) of Epidemiology and Public Health, who monitors Arantxa and other children in Valencia, the questionnaires are key to obtain information not only on what they eat or their habits, but also their mental development. Computer games are also used to study their brain from the age of four. They are more objective to measure your cognitive abilities. In one of the exercises used, objects appear on the screen for seven minutes - a boat, a ball, a horse - and the little ones must always press the space bar on the keyboard, except when an X appears. It is used to measure your attention span.
From the data obtained with this same computer game -in Asturias, Guipuzkoa, Sabadell and Valencia-, the researchers determined in a study published in 2017 Environmental International Greater exposure to nitrogen dioxide pollution, primarily during pregnancy and, to a lesser extent, after birth, is also associated with poor attentional function in children aged 4 to 5. "With pollution, we've found a strong relationship with attentional function, memory, mental development, and motor skills; which is also very consistent with the results of other studies," emphasizes Mònica Guxens, an ISGlobal researcher who participated in this scientific work and is currently director of the INMA project. "However, we haven't found any association with ADHD (attention deficit hyperactivity disorder), autistic traits, depression, anxiety, or aggression, although other cohort studies in the US have."
"With pollution, we've found a strong relationship with attentional function, memory, mental development, and motor skills; which is also very consistent with the results of other studies," emphasizes Mònica Guxens, director of the INMA project.
"We still have many questions to answer," emphasizes Guxens, who explains that research is now seeking to better understand the relationship between pollution and childhood obesity or the potential precursors of cardiovascular diseases in the future. However, over the course of 20 years of the project, it has already been shown that air pollution, in addition to causing illnesses in children (such as asthma or other respiratory problems), can also affect the functional abilities of children, even if they are healthy. To what extent does having less cognitive development or respiratory function affect their life? "It's not clear, but ideally, the brain should grow to its full potential; no one wants to have less development," responds the INMA director.
"It's not the same if someone has an IQ of 85 and it drops by 5 points to another with 135 and it drops to 130," notes researcher Jordi Sunyer, who emphasizes that each case is individual and depends on the predetermined potential of each child. "We're not certain that these functional impacts are very decisive for a person's development, well-being, or health, but what we do know is that at the collective level, this has great socioeconomic importance," he emphasizes. "These differences are very noticeable on the scale of an entire neighborhood or an entire population exposed to high levels of pollution."
