The abundance, distribution and composition of marine debris (> 5 cm) and small microplastics (11 μm) from five rivers in South Eastern Nigeria was investigated. This study provided the first assessment of the type and quantity of marine litter and microplastics in Nigeria. A total of 3,487 macrodebris items/m 2 were counted with the following distribution: plastics (59%), metal (10%), cloth (7%), paper/cardboard (7%), rubber (7%), glass/ceramics (5%), medical and agro-based waste (3%), and wood (2%). The cleanliness of the river assessed with clean coast index ranged from "very clean" to "extremely dirty". Microplastics abundance ranged from 440 to 1,556 particles/L, with high accumulation at downstream. Fragment shape was most abundant while fiber and film followed. The distribution of plastic types was PET (29%), PE (22%), PVC (16%), PP (14%), and others (6%). Significant relationship was found between the total abundances of microplastics and different macrodebris groups suggesting that microplastics were abundant in areas where the macrodebris abundance was high. Our results provide baseline information for future assessments. Management actions should focus on input prevention including proper waste management, recycling of plastics, and strict penalties for illegal dumping of wastes.

The abundance, distribution and composition of marine debris (> 5 cm) and small microplastics (11 μm) from five rivers in South Eastern, Nigeria was investigated. This study provided the first assessment of the type and quantity of marine litter and microplastics in Nigeria. A total of 3487 macrodebris items/m2 were counted with the following distribution; plastics (59 %) > metal (10 %) > cloth (7 %), paper /cardboard (7 %), rubber (7 %) > glass/ceramics (5 %), medical and agro-based waste (3 %) > wood (2 %). The cleanliness of the river assessed with clean coast index (CCI) ranged from “very clean” at Okumpi and Obiaraedu river to “extremely dirty” at Nwangele river. Microplastics abundance ranged from 440 to 1556 particles/L, with high accumulation at downstream. Fragment shape was most abundant while fiber and film followed. The distribution of plastic types was; PET (29 %) > PE (22 %) > PVC (16 %) > PP (14 %) > other (6 %) respectively. Significant relationship was found between the total abundances of microplastics and different macrodebris groups suggesting that microplastics were abundant in areas where the macrodebris abundance was high. Our results provide baseline information for future assessments. Management actions should focus on input prevention including proper waste management, recycling of plastics, and strict penalties for illegal dumping of wastes.

Microplastics are ubiquitous tiny plastic particles (< 5 mm) nonbiodegradable and have large surface area in the environment or the body of living things from anthropogenic activities or fragmentation of plastic debris. Though found in sea food and human body, their health implications are still speculative. A major reason for dearth of information on this topical issue is the lack of standard methods for analyzing microplastics in more complex environmental matrices. In the present review some methodologies for analyzing microplastics reported in the period 2000 to 2018 have been documented with the aim of assessing which methods is most suitable and in what matrix. The following methods have been studied: CHN analyzers, pyrolysis-gas chromatography/mass spectroscopy (PyrGC/MS), optical microscopy, fourier transform infrared microspectroscopy (Micro-FTIR), raman microspectroscopy (RMS) and scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDS). Studies have been conducted with often a combination of two methods; one separating and the other quantifying which can be problematic moreso in living tissue where there is no harm reported as at the time of this study. However, microplastics have become a cause for concern and advance studies are required to unravel the potential risk of their presence in our food and environment.

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Polycyclic aromatic hydrocarbons (PAHs) exposure is among the leading air pollutants associated with diverse adverse health effects due to their persistent, bio-accumulative and toxic characteristics. Children are most affected by these pollutants, yet studies directly related children to these pollutants are scarce in Nigeria. In this study, blood and urine from 36 children between the ages 4-14 years were collected as per sterile procedures by a licensed phlebotomist from the antecubital fossa into BD vacutainer tubes® while a mid-stream urine sample into acid-washed 120 mL BD vacutainer urine cups and stored in refrigerator at –4˚C for 6 hours, then each 5 mL was extracted with 10 mL of pentane and analyzed for 15 PAHs using GC-MS. Results revealed that PAHs concentrations (53.48 to 70.8 μg/dL) in blood was lower than in urine (94.98 to 115.04 μg/dL). Mean values had no significant (p>0.5) differences between schools, possibly due to the fact that all schools were experiencing similar anthropogenic disturbances. At 5% level of significance, positive and strong correlationships (r=0.83, r=0.73) were observed for fluorene-fluoranthene (FLa) and benzo (a) anthracene-FLa respectively in blood samples. Two and three rings PAHs had generally low concentrations in both blood and urine. Despite being the most distributed compound, the concentration of dibenzo (a,h) anthracene was highest for urine than in blood. Urine PAHs showed higher concentration of carcinogenic PAHs than blood. Elimination ratios (ER) such as for acenaphthene (0.06) and anthracene (Ant; 0.11) were considered low while values such as for FLa (1.36) and indeno [1, 2, 3-cd] pyrene (1.55) were considered high ER. Trends in elimination ratios showed close similarity. In conclusion there was elevated PAHs in blood and urine of children with consequent high carcinogenic and then non-carcinogenic risks. This research is significant in setting the stage for more detailed work at same time alerting policy makers on the need for urgent mitigation steps that will reduce children exposure to this class of dangerous pollutants.