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Maternal air pollution exposure puts unborn babies at risk in South Africa

PollutionSouth Africa | Pregnant mothers living in air pollution hotspots in South Africa risk bearing a child with a congenital birth anomaly, specifically orofacial cleft lip and palate (CLP).

This is according to research done by the South African Medical Research Council (SAMRC) in partnership with surgeons, researchers and Operation Smile that was presented on 13 February at the Climate Child Health Series: The Impact of Climate Change on Newborn Health Outcomes held online by the US Child Health Task Force and UNICEF.

The research draws together cases of patients with CLP from 2006 to 2020. Drawing from two data bases, a total of 2 515 cases were studied in relation to air pollution assessed at the mother’s residence. The research identifies an association between the increasing trend in CLP and a mother’s exposure during early pregnancy to particulate matter (PM) air pollution, PM10 and PM2.5.

Orofacial cleft lip and palate explained:

CLP are birth anomalies that typically affect a baby’s lip or mouth and nose because these parts do not form properly during pregnancy. This may happen during weeks four and seven of pregnancy. When a baby is developing, body tissue and special cells from each side of the head join to make the face.

There are several possible causes of CLP including genes, what the mother eats and drinks, whether a mother smokes, uses a certain type of medication during pregnancy and another factor is the environment in which the pregnant woman lives. The latter has been less explored which is why this research was conducted.

Dr Caradee Wright, Chief Specialist Scientist at the SAMRC’s Environment and Health Research Unit, said, “Air pollution levels are known to be high in South Africa, coming from coal-fired power stations, traffic, domestic fuel burning, mining, industry and other sources. We wanted to explore whether a mother’s exposure to air pollution affected her baby’s risk of cleft lip and palate in South Africa.”

CLP birth hotspot clusters were found in district municipalities in the provinces of Gauteng, Limpopo, North-West, Mpumalanga, and Free State.

The use of the research findings:

These findings emphasise the need for more stringent air quality management in South Africa to protect the health of unborn children. The country has National Ambient Air Quality Standards and Air Pollution Priority Areas where air quality should be strictly managed.

Information needs to be provided to mothers regarding the risks that air pollution poses to their unborn child – especially in very early pregnancy so it’s important that if someone wants to fall pregnant, they try and limit air pollution exposure. One can do this by avoiding making fires indoors without adequate ventilation, and not walking or exercising on busy roads during peak traffic hours.

Patients that have CLP experience a higher mortality risk and deal with the adverse effects of physical challenges such as speech impediments, physical deficiencies in appearance, and psychosocial issues. Added to the difficulties confronted by children with CLP are nutritional problems caused by the inability to consume food. The malnutrition that is a result of CLP is not properly recorded because the death certificates list these deaths as malnutrition. The research conducted demonstrates the use of a multidisciplinary approach, where multiple disciplines collaborate and share data on all maternal information and pollutant volumes in all provinces of South Africa. The multi-lateral work can prevent CLP where possible and reduce suffering and financial burden on those affected.


The full research paper written by Dr Caradee Wright can be found here: The Risk of Orofacial Cleft Lip/Palate Due to Maternal Ambient Air Pollution Exposure: A Call for Further Research in South Africa - PubMed (

For more enquiries:

  1. Dr Caradee Wright
    (Chief Specialist Scientist: Environment and Health Research Unit)
  2. Yolanda Phakela
    (Public Relations Manager)
    Cell: 073 801 3691
Release date
Cleft lip & Palate
SDG13: Climate Action

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