Data on macro(micro)plastics and hydrophobic organic contaminants in the Gulf of Guinea coastal psammitic beaches.

The ubiquity of microplastics in coastal environments and marine ecosystems is a significant concern because they have a strong affinity for organic contaminants. This paper presents the first reported data on hydrophobic organic contaminants (HOCs) and microplastics particles (MPs, 1-5 mm) in lagoon and beach sediments along the Gulf of Guinea coastline (SE Atlantic). Sampling was carried out between August and November 2019. Ten sites were designated for each location, and sediment samples were taken along three transects: high waterline, drift waterline, and current waterline. Sediment samples were extracted through density floatation procedure and sieving. Primary data on polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) associated with MPs are provided, as well as detailed information on sampling coordinates, plastic types, and their relative abundance. Refer to the research publication ``Microplastics and associated organic pollutants in beach sediments from the Gulf of Guinea (SE Atlantic) coastal ecosystems'' (Fred-Ahmadu et al., 2022) for detailed discussion and interpretation of the reported data.

Microplastics and associated organic pollutants in beach sediments from the Gulf of Guinea (SE Atlantic) coastal ecosystems.

Microplastics (MPs) are emerging pollutants of global concern due to their pervasiveness, sorptive capacity for organic and inorganic pollutants, and direct and indirect toxicity to organisms and ecosystems. This study aimed to assess the concentration and the statistical difference in the concentration of microplastic-sorbed organic pollutants from two ecosystems, the marine and estuarine lagoon. Surface sediment from the estuarine lagoon and marine ecosystems were sampled for microplastics (1-5 mm). A total of 3680 MP particles were collected. The plastics were analyzed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). ∑PAHs, ∑PCBs and ∑OCPs were between 0.00 and 0.32 mg/kg, 0.00-0.53 mg/kg and 0.04-2.02 mg/kg, respectively. The results showed a correlation of -0.2, 0.8 and 0.2 between the number of MPs and the concentration of PAHs, PCBs and OCPs, respectively, suggesting that the potential risk of accumulation of plastic-sorbed PCBs is higher than those of OCPs and PAHs. Mann Whitney U test (at 95% confidence level) indicated no statistical difference in the concentration of organic pollutants in lagoon and beach MPs. In addition, we found no significant difference in the accumulation of organic pollutants in MPs from beach drift and high waterlines. The result suggests that the concentration of microplastics-sorbed organic pollutants in both ecosystems is comparable and likely to pose similar potential risks. We recommend that plastic pollution in all ecosystems require attention.

Occurrence and distribution of micro(meso)plastic-sorbed heavy metals and metalloids in sediments, Gulf of Guinea coast (SE Atlantic).

The pervasive existence of microplastics (MPs) and toxic metals is raising environmental and health concerns. Plastics are essentially a complex mixture of chemicals, but exposure to the aquatic environment increases their complexity through contaminant desorption/sorption. The aim of this study was to establish baseline data on the elemental occurrence and distribution of potentially toxic and geochemical metals/metalloids in microplastics 1-5 mm and mesoplastics (> 5 mm - 1 cm) along designated coastlines of the Gulf of Guinea (Nigeria) in addition to enabling more comprehensive ecotoxicological risk assessment. The concentrations of twenty-six metals: aluminium (Al), antimony (Sb), arsenic (As), barium (Ba), boron (B), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), potassium (K), selenium (Se), sodium (Na), silicon (Si), silver (Ag), strontium (Sr), thallium (Tl), titanium (Ti), vanadium (V), and zinc (Zn), associated with beach MPs, pristine, and lagoon plastics were determined after extraction in 10% nitric acid and analysis using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The distribution of MPs was variable, with 3680 particles identified along the drift and high waterlines across designated shoreline locations. The beach MPs were dominated by polyethylene (PE), polypropylene (PP), and polystyrene (PS), whereas lagoon-sourced plastics were characterized by polyethylene terephthalate (PET), polystyrene (PS), and polyurethane (PUR). Metal concentration was higher when associated with foam plastic (PS, PUR, PEVA) compared to hard plastic (PE, PP, PET) samples. The results showed that all samples had slightly elevated Al, Fe, Mn, and Zn concentrations, suggesting potential sorption interactions and plastic additive influences. Notably, foam MPs had a stronger affinity for metals. This study emphasizes the critical role of microplastics in serving as vectors for toxic metals. Except for Cd, pollution indices such as the potential contamination index (PCI), hazard quotient (HQ), and modified hazard quotient (mHQ) indicated low severity contamination of beach and lagoon MPs by heavy metals. However, considering long-term accumulation of sorbed metals, their potential toxicity to marine biota may be considerable.

Dataset on microplastics and associated trace metals and phthalate esters in sandy beaches of tropical Atlantic ecosystems, Nigeria.

This article presents data on the occurrence and distribution of phthalate esters and metals associated with microplastics (MPs) (1-5 mm) collected from four beaches in the tropical Atlantic ecosystems, Nigeria, Gulf of Guinea. Information on microplastics extraction by density flotation with saturated NaCl and polymer identification with attenuated total reflectance infra-red spectroscopy (ATR-FTIR) is also provided. Analysis of six phthalate esters (PAEs) (dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DnBP), benzyl butyl phthalate (BBP), di (ethyl hexyl) phthalate (DEHP), and di n-octyl phthalate (DnOP)) associated with the microplastics by performed using Gas chromatography-mass spectroscopy (GC-MS). Metals including Ag, Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Si, Sr, Ti, Tl, V, and Zn were analysed by inductively coupled plasma-optical emission spectrometry (ICP-OES). The data present the separation of microplastics from sediment, extraction with cyclohexane/ethyl acetate (1:1, v/v) and 10% HNO3 for phthalate esters and metals, respectively, and the determination of target analytes concentrations. The compositional distributions of MPs and levels of carcinogenic and toxic metals and phthalate esters are presented. The dataset could be used for the evaluation of ecological risk associated with PAEs in the marine ecosystems.

Interaction of chemical contaminants with microplastics: Principles and perspectives.

Scientific evidences abound of the occurrence of plastic pollution, from mega- to nano-sized plastics, in virtually all matrixes of the environment. Apart from the direct effects of plastics and microplastics pollution such as entanglement, inflammation of cells and gut blockage due to ingestion, plastics are also able to act as vectors of various chemical contaminants in the aquatic environment. This paper provides a review of the association of plastic additives with environmental microplastics, how the structure and composition of polymers influence sorption capacities and highlights some of the models that have been employed to interpret experimental data from recent sorption studies. The factors that influence the sorption of chemical contaminants such as the degree of crystallinity, surface weathering, and chemical properties of contaminants. and the implications of chemical sorption by plastics for the marine food web and human health are also discussed. It was however observed that most studies relied on pristine or artificially aged plastics rather than field plastic samples for studies on chemical sorption by plastics.

A new method for assessment of sediment-associated contamination risks using multivariate statistical approach.

This paper presents the assimilation of heavy metal concentration data from sequential extraction method (SEM) with metal toxicity factors to develop and propose two new sediment quality indices modified hazard quotient (mHQ) and ecological contamination index (ECI), to predict the potential ecological risks associated with sediment contamination. Chemical speciation data of five heavy metals: cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) from five coastal aquatic ecosystems of the Equatorial Atlantic Ocean were used in the assessment of the degree of heavy metal contamination. Evaluation based on ECI indicated that sediments of most aquatic ecosystems were considerably to highly contaminated. The results showed that the proposed indices are reliable, precise, and in good agreement with similar existing indices used for evaluating the severity of sediment-associated contamination by heavy metals. The principal component analysis (PCA) and factor analysis indicated that heavy metals in the benthic sediments were mostly from anthropogenic sources. •New indices - modified hazard quotient (mHQ) and ecological contamination index (ECI) - were developed for predicting sediment-associated risk adverse effects.•Newly proposed indices agree closely with the existing pollution indices.•Pollution indices reveal significant anthropogenic contamination by Cd and Pb.

Toxic metals in cigarettes and human health risk assessment associated with inhalation exposure.

This study evaluated the concentrations of cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), lead (Pb), and zinc (Zn) in 10 branded cigarettes commonly consumed in Nigeria. Chemical sequential extraction method and pseudo-total metal digestion procedure were used for extraction of metals from filler tobacco and filter samples. Samples were analyzed using flame atomic absorption spectrometry (FAAS). The filler tobacco of cigarettes had Cd, Cu, Fe, Mn, Pb, and Zn concentrations in the ranges of 5.90-7.94, 18.26-34.94, 192.61-3494.05, 44.67-297.69, 17.21-74.78, and 47.02-167.31 µg/cigarette, respectively. The minimum and maximum concentrations in the filter samples were 8.67-12.34 µg/g of Cd, 1.77-36.48 µg/g of Cu, 1.83-15.27 µg/g of Fe, 3.82-7.44 µg/g of Mn, 4.09-13.78 µg/g of Pb, and 30.07-46.70 µg/g of Zn. The results of this study showed that the concentrations of heavy metals in the filler tobacco samples were consistently higher than those obtained for the cigarette filters except for Cd. Toxic metals were largely found in the most labile chemical fractions. Moderate to very high risks are found associated with potential exposure to Cd and Pb. The carcinogenic risks posed by Cd and Pb ranged between 1.87E-02 and 2.52E-02, 1.05E-03 and 4.76E-03, respectively, while the non-carcinogenic risk estimates for Cd and Pb were greater than 1.0 (HI > 1). Toxic metals in cigarette may have significant carcinogenic and non-carcinogenic health effects associated with inhalation exposure. Continuous monitoring and regulations of the ingredients of imported and locally produced tobacco products are advocated.

Trace metal levels in fruit juices and carbonated beverages in Nigeria.

Trace metal levels in selected fruit juices and carbonated beverages purchased in Lagos, Nigeria were determined using atomic absorption spectrophotometer (Unicam model 969) equipped with SOLAAR 32 windows software. Fruit juices analysed were grape, pineapple, apple, orange, lemon juices and their brand names were used. Some carbonated drinks were also evaluated for metal levels. Trace metals investigated were Cr, Cu, Pb, Mn, Ni, Zn, Sn, Fe, Cd and Co. Trace metal contents of fruit juices were found to be more than the metallic contents of carbonated beverages. Pb level in the fruit juices ranged from 0.08 to 0.57 mg/l but was not detected in the carbonated drinks. Concentrations of Pb in lemon juice and Mn in pineapple juice were relatively high. Cd and Co were not detected in the selected juices and beverages. Additionally, Pb, Cu, Cr and Fe were not detected in canned beverages but were present in bottled beverages. However, the metal levels of selected fruit juices and carbonated beverages were within permissible levels except for Mn in pineapple juice and Pb in lemon juice.