Poor air quality is linked to impaired visual cognition in infants during the first two years of life. This is according to a study by the University of East Anglia (UAE) in the United Kingdom (UK). The study revealed that babies living in homes with lower air quality showed lower visual working memory scores at six and nine months. And slower visual processing speed from six to 21 months when controlling for family socio-economic status.
The study was based in a rural community called Shikar in Uttar Pradesh in India. This state was chosen because of the known strong impact of poor air quality that residents experience.
“We are concerned with how the very small particulate fragments with a diameter of <2.5 μm; PM2.5 are of major concern as they can move from the respiratory tract into the circulatory system reaching the brain. The brain may also be sensitive during infancy due to an immature detoxification response and the developing process,” said Lead researcher Professor John Spencer, from UEA’s School of Psychology.
This research is particularly important in the context of SA because PM10-2.5 and PM2.5 aerosol samples are present and can be collected in the air we breathe from various different sites.
According to the Swiss IQ Air Quality Index 2022 Report, air pollution in the country was 4.7 times the World Health Organisation’s (WHO) annual air quality guideline value.
The Air Quality Index report shows that as of March 16, 2023 , the top 10 towns and cities with the highest air pollution in South Africa are Meyerton, Vereeniging, Sasolburg, Johannesburg, Ga-Rankuwa, Eastleigh, Kwambonambi, Klerksdorp, Pretoria and Springs.
In SA, poor air quality has been linked to poor maternal and neonatal health outcomes, leading to lifelong disabilities.
Trouble concentrating and remembering
Dr Jacqueline Bezuidenhout, Developmental Paediatrician at Charlotte Maxeke Johannesburg Academic Hospital, says that exposure to poor air quality and other environmental toxins such as heavy metals during gestation and in the first year of life may alter how an infant’s brain develops.
The findings in the report indicate that poor air quality (PM2.5) is associated with slower visual processing speed in the first two years of life and poorer visual working memory scores within the first year. In addition, exposure to poor air quality is also a risk factor for child emotional and behavioural problems which can have severe impacts on families.
A lot of families in the report are shown to be using cow dung to cook with or wood burners. Spencer says that cooking emissions were one of the big causes that were revealed in the research. Cooking methods that are similar and widely used by households that live in rural and informal areas in SA.
“Opening cooking methods and the different traditional methods of cooking in the home were found to have an impact on the cooking fuel in the home and on poor air quality. The data shows spikes of poor air quality during the cooking times during the day.”
In South African homes
Children living in SA are exposed to air pollution inside the house and outside (ambient air) their homes and schools. The 2019 Child Gauge issue, written by Maylene Shung-King, Lori Lake, and others, notes the disease risks from these exposures are high for children even at extremely low levels of exposure because they are particularly vulnerable at different stages of development,
Children living in rural areas of KwaZulu-Natal, Limpopo and Eastern Cape provinces are also exposed to toxic fumes due to the widespread use of burning wood and coal for cooking in the home, which releases hazardous chemicals which may cause respiratory disease.
The Child Gauge indicates that some of the effects of air pollution can cause premature death.
The Mpumalanga Highveld Priority Area is an area known for its air pollution that is harmful to people’s health. The pollution is primarily caused by emissions from facilities operated by Eskom and Sasol.
“South African babies born today have chemicals in their systems – from dichlorodiphenyltrichloroethane (DDT) which is used for malaria control in four provinces to phthalates found in plastic packaging, pipes, medical tubing and toys,” reads the issue.
The chemicals mentioned above are known to be linked to a global increase in childhood brain cancers, asthma, leukaemia, early onset of puberty, attention deficit hyperactivity disorder (ADHD), genital disorders in boys, and life-threatening birth defects.
The environment and child development
Bezuidenhout says the impact experienced by a developing brain is lifelong and is especially critical in the first two years of life after a baby is born.
She explains that brain development starts a few weeks from when the embryo is formed, and then the brain continues developing throughout gestation, continuing for up to 24 years after birth.
“All the critical structural components of the brain are formed in the first few months of gestation including the formation of the neural cells, the migration of these cells to form the cortex of the brain and the important connections (synapses) between these neurons. Other vital processes, such as myelination, continue up until early adulthood. However, the first 1000 days, which are from conception until two years after birth, are the most critical for a child’s brain development and is when the brain is very sensitive to harm.”
A mother’s exposure to environmental pollutants like air pollution or harmful substances such as smoking, or alcohol, may not only harm the mother but the unborn baby as well. This highlights the ways in which environmental factors can change the form and functioning of the brain.
“There is no standardised way to determine or predict the kind of impact that environmental pollutants can have on a child. Later on in life, children may experience subtle disabilities like ADHD or learning challenges or more extensive challenges such as an intellectual disability,” she says.
The way that children living in SA grow and develop is linked to the quality of their environmental exposure. Bezuidenhout notes that this extends to food access, safety and security, early childhood development programs, access to public health facilities, and other aspects needed to provide children with the opportunity for better health outcomes.
A need for more research
According to the WHO, over 600,000 children died globally from air pollution-induced respiratory infections in 2018. However, research on how children living in SA are impacted is limited. Globally, 92% of adults and children breathe ambient (outdoor) air that exceeds WHO limits.
The guidelines on air quality set by WHO state that the annual emissions of PM2.5 should be at or below concentrations of 5 μg/m3. In 2022, only 13 (9.9%) out of the 131 countries and regions studied were adhering to this number.
Child Gauge describes the research in South Africa on the impact of poor air quality as limited due to a lack of funding and a failure to recognise the urgency and extent of the problem.
Bezuidenhout adds that research is also difficult to conduct on this topic because it is not uniform. A person may be living in an environment close to a factory or a highway, where there will be lots of exhaust transmissions so it’s challenging to generalise the findings.
“The quality of the air they breathe is different to someone living on the outskirts of a town. That’s why locally based research is important because interpreting these results and trying to make them uniform is difficult.”
She says that further research needs to be conducted, and the information provided by this report is necessary to help in the enforcement and strengthening of policies and governance within SA to ensure better developmental and health outcomes for our children. – Health-e News