A study carried out by researchers at the University of Port Harcourt, Rivers State, has found high levels of arsenic, lead, mercury and cadmium detected in the breast milk of diabetic and non-diabetic postpartum mothers.

The peer-reviewed study titled ‘Comparison of toxic heavy metals in the breast milk of diabetic and non-diabetic postpartum mothers in Yenagoa, Nigeria’ was published in the PLoS One journal on April 7, 2023.

Arsenic is highly toxic in its inorganic form. Contaminated water used for drinking, food preparation, and irrigation of food crops poses the greatest threat to public health from arsenic. Lead is a naturally occurring toxic metal found in the earth’s crust.

Mercury is toxic to human health, posing a particular threat to the development of the child in utero and early in life; while cadmium exerts toxic effects on the kidneys as well as the skeletal and respiratory systems.

The researchers utilised a cross-section of 72 diabetic and 72 non-diabetic postpartum mothers from three public hospitals in Yenagoa, the capital of Bayelsa State.

The researchers said the concentration of the toxic heavy metals detected in the two groups were above the World Health Organisation’s permissible limits, thus showing evidence of risk to the health of the mother and neonate.

According to them, heavy metals exposure could trigger suppression of cytokine production and lower immunity as they bind to albumin and enter the breast milk.

The researchers noted, “Yenagoa is a seaside town with staple consumption of charcoal smoked fish, heavy agricultural fertiliser use, and widespread clandestine (illegal) crude oil refining. It is also the seat of legal crude oil exploration and petrochemical activities in the Niger Delta region. It has experienced several crude oil spills from 1976 till recent times resulting in environmental degradation and the possible release of heavy metals into the environment.

“The research team wonders if maternal diabetes would worsen the excretion of toxic heavy metals in breast milk. A literature search in the major research databases such as MEDLINE, PubMed, and ProQuest yielded few peer-reviewed publications on the subject matter.

“The knowledge gap motivated the research team to embark on a study to compare the concentration of heavy metals in the breast milk of diabetic and non-diabetic postpartum mothers in Yenagoa, Bayelsa State, Nigeria. To the best of our knowledge, this study is the first to measure heavy metals in the breast milk of diabetic lactating mothers.”

They, however, said more toxicological research on mother and child health might be necessary to validate the conclusions of the study.