Bisphenol-A (BPA) in Foods commonly consumed in Southwest Nigeria and its Human Health Risk.

Bisphenol-A (BPA) is a synthetic chemical ubiquitous in the environment and listed as an endocrine disruptor. It has the tendency of migrating into food stored in materials containing it. This study, therefore, determines the concentrations of BPA in foods commonly consumed in Southwest Nigeria by the adult population and also estimates the risk associated with human exposure. Eight different food categories were selected for this study. Standard QuEChERS protocol was used for sample extraction and analysed using gas chromatography-mass spectrometry (GC-MS). Vegetable oil had the highest BPA concentration (28.4 ng/g). This was followed by aquatic canned fish (26.3 ng/g), canned beef (21.3 ng/g) and crayfish (17.5 ng/g). These concentrations were below the 600 ng/g limit of the European Commission for BPA in foods. Bisphenol-A was not detected in raw beef, chicken, cheese, apple, tomatoes, beans and rice; and chicken eggs. The adult population had an average dietary intake of 30.4 ng/kg bw/day. There is no likely occurrence of harmful health effects of BPA in the selected foods with respect to the current concentrations found therein. However, routine monitoring is recommended to prevent human exposure to BPA.

Oxygenated Volatile Organic Compounds (Anti-freezing Agents) in Decorative Water-based Paints Marketed in Nigeria.

BACKGROUND: Consumer products such as paints are a potentially significant source of volatile organic compounds (VOCs) and oxygenated VOCs. Paints for construction and household use have been rapidly changing from oil-based to water-based paints and are one of the commonly identified sources of oxygenated VOCs in indoor environments. OBJECTIVES: Four different anti-freezing agents were identified and analyzed in 174 waterbased paint samples, purchased from popular paint markets in two metropolitan cities in Nigeria, Lagos and Ibadan. METHODS: Paint samples were solvent extracted using acetonitrile and milli-Q water. Antifreezing agents in the extracts were identified and quantified using gas chromatography (GC)-mass spectrometry and a GC-flame ionization detector, respectively. DISCUSSION: Four different anti-freezing agents were identified in the samples, ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol. Their levels ranged from 1,000-1,980 ppm, diethylene glycol; 1,000-3,900 ppm, triethylene glycol; 1,090-2,510 ppm, propylene glycol and 1,350-2,710 ppm, ethylene glycol. Levels of anti-freezing agents in all of the paint samples were above the permissible limits of the European Union for VOCs in paints of 500 ppm. Results of multivariate statistical analyses clearly showed that triethylene glycol was the most commonly used anti-freezing agent in paints despite its numerous harmful health effects. CONCLUSIONS: We concluded that water-based paints marketed in Nigeria contain high concentrations of anti-freezing agents, which have harmful environmental and human health effects, especially to sensitive individuals such as children. COMPETING INTERESTS: The authors declare no competing financial interests.

Lead and Cadmium Levels in Residential Soils of Lagos and Ibadan, Nigeria.

BACKGROUND: Lead and cadmium are components of paints sold in Nigeria. These heavy metals are associated with adverse neurological, cardiovascular and other human health effects. OBJECTIVES: This study assesses the levels of lead and cadmium in topsoil of residential areas in Lagos and Ibadan potentially resulting from painting of buildings. METHODS: Samples were pre-treated prior to metal determination using atomic absorption spectrophotometry. Metal speciation was determined using modified Tessier sequential extraction. Soil characteristics were determined by standard methods. Soil contamination was assessed using contamination factor, geo-accumulation and pollution load indices. The United States Environmental Protection Agency integrated exposure uptake biokinetic (IEUBK) model was used to estimate and predict children's blood lead levels (BLL). RESULTS: Lead and cadmium concentrations in residential areas in Lagos and Ibadan ranged from 1.56-419 mg/kg and not detected-2.8 mg/kg, respectively. Metal contamination factor and pollution load index were highest at the Lagos low income settlement. Results of IEUBK modelling showed that the Lagos low income settlement had the highest probability density for children between 1-7 years of age with an estimated BLL of >10 µg/dL. This population made up less than 0.01% of those within this age range. CONCLUSIONS: Lead and cadmium concentrations in soil around the residential buildings were higher than those in the control sample. Contamination factor and pollution load index showed significant contamination in average and low income settlements. These results suggested that there was accumulation of the metals in the soil, which can persist in the environment. This may pose serious health risks, especially to vulnerable groups such as children.

Examination of Lead and Cadmium in Water-based Paints Marketed in Nigeria.

BACKGROUND: In spite of the availability of substitutes for lead and cadmium compounds in paints, manufacturers continue to produce paints with high levels of these metals. As the population continues to grow and there is a continued shift from oil-based to water-based paints, the sales and use of these paints will increase the exposure of humans and the environment to these metals. OBJECTIVES: We measured the levels of lead (Pb) and cadmium (Cd) in 174 paint samples marketed in Lagos and Ibadan, Nigeria. Paint samples from different manufacturers registered with and without Standards Organization of Nigeria (SON) were considered. METHODS: Samples were acid digested using a microwave digester and the levels of the elements were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). DISCUSSION: The levels of Cd and Pb (dry weight) in all samples ranged from 98-1999 µg/g and 170-3231 µg/g, respectively. All the samples were above the permissible limits of 90 ppm of the US Consumer Product Safety Commission and 100 ppm limit of the European Union (EU) for Pb and Cd in paint. CONCLUSIONS: We concluded that water-based paints marketed in Nigeria still contain substantial amounts of lead and cadmium which are detrimental to human health and the entire ecosystem. These metals are among the EU priority metals due to the increased risk of occupational exposure to humans and vulnerable groups such as children.