Chemistry

Current problem facing researchers globally is microplastics as well as toxic chemical pollution of the ecosystem. Microplastics carry toxic chemicals in the ecosystem.serving as a vector for transport. In this study, a review of the literature has been conducted with the following objectives: (1) to summarise the concentrations of toxic chemicals such heavy metals and hydrophobic organic contaminants sorped on microplastics; (2) to evaluate their spatial distribution regarding adsorbed contaminant (3) to discuss plausible mechanism by which microplastics adsorp or desorp toxic chemicals in the environment; (4) to discuss implications of their occurrence in air, water and soil media; and (5) to discuss the impact of ingested microplastics to human health. Microplastics are ubiquitous environmental contaminant. Concentrations of sorped toxic chemical varied with location which represents a local problem; industrialized areas (especially areas experiencing crude oil related activities...

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 rel...

The microplastics in the environment is a novel problem to scientists, public media, governmental and non-governmental organizations. The major problem is from the difficultness of removing them from the ecosystem. Elsewhere studies are being conducted while in Nigeria studies are relatively lacking. Production (10.3 %) and consumption (6.5 %) of plastics are on the increase annually, thereby, causing an increase in the amount of plastic waste generated annually. Finally, from such studies, data generated will provide insight and understanding into the extent of microplastic pollution in Nigeria. Furthermore, the data will be important not only for both remediation and minimization of effects but could be employed in averting occurrence through policies such as ban on some types of plastic uses in Nigeria. In this study, four manually generally microplastic types (PVC, acrylics, polyesters, silicones) were evaluated for heavy metals (Pb, Cd, Hg, and As) adsorption at optimized pH by...

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...

Despite recording the worst heavy metal disaster involving children, there is still scarcity of information on risk assessment of playground soils in Nigeria. In this study, thirty-six soil samples at 05 cm depth were collected from nine playgrounds in Owerri metropolis during the dry and rainy seasons. Five heavy metals were fractionated into six chemical fractions using a modified sequential extraction scheme and mean concentrations quantified by AAnalyst 400 Perkin Elmer AAS. Predictive risk models were used to obtain information about the risk of metals contamination to children using these playgrounds for longer periods. These reveal that there were no significant differences in the mean values of bioconcentration factors of all five metals in the various playgrounds for the two years of data. Even though risk values for both dry and rainy season followed the same trend, it was observed that the Zinc showed highest bioconcentration factors (1.6), average daily dose (230.08 mg/k...

Knowledge of variation in metal concentrations of playground soil in dry and rainy season could assist in controlling metal accumulation in children if playtime is regulated according to seasons. The present investigation was designed to find out the existence and trend of such variation. Thirty six surface soil samples from nine playgrounds of Owerri metropolis were collected during the dry season and rainy seasons of 2012 and 2013 and were digested in Pyrex glassware using nitric acid. Total heavy metal concentration was determined by AANALYST 400 Perkin Elmer absorption spectrophotometer and coefficient of variation was used to categorize variability. Results demonstrated significant seasonality for all five heavy metals with major variability observed between dry and the rainy season. Metal concentrations showed zinc as highest metal in both seasons whereas cobalt was lowest metal with Ni occasionally being lowest in the rainy season. The variation of metals concentrations in pl...

Pollution scenario of water from River Uramurukwa was investigated. In both rainy and dry season, 5 water samples each taken from different points were analysed to determine physico-chemical parameters and heavy metals (using Atomic Absorption Spectrophotometer). The investigated physico-chemical parameters for both dry and rainy season respectively ranges from: temperature (32-32.4C, 29-29.8C), electrical conductivity (15.67-2.00 μS/cm, 7.31-61 μS/cm), pH(5.2-5.7, 5.9-6.7), total dissolved solids (2.67-3.98 mg/L, 3.29-5.33 mg/L) and TSS (4.43-6.64 mg/L,4.88-5.84 mg/L). The analysed major ions were: sodium (Na)(1.30-1.67 mg/L, 1.76-2.38 mg/L), potassium (K)(0.819-0.898 mg/L, 0.081.89 mg/L), magnesium (Mg)(1.13-2.78 mg/L, 1.23-2.86 mg/L), calcium (Ca)(22.92-24.6 mg/L, 13.9-43.9 mg/L), nitrate (NO3 )(0.91-0.96 mg/L, 0.56-0.97 mg/L), phosphate (PO4 3)(0.34-1.65 mg/L, 1.07-2.17 mg/L) and sulphate (SO4 )(23.4-24.8 mg/L, 21.02-29.18 mg/L). The investigated heavy metals were: lead (Pb), zi...

Ohaji Egbema is known for its oil production and exploration activities and so crops grown in this area could be contaminated. Chemical speciation was carried out on four commonly grown food crops in the area so as to determine the level of metal contamination. The samples were analyzed sequentially and the metal species in the extract determined by ASS. Results revealed that mean concentrations of all studied metals to fall within the WHO/FAO permissible limits. Significant bioavailability was observed for Pb in Okoro (0.67) and Orange (0.7). Zn showed the highest concentration and its bioavailability was highest for Okoro (12.6)>Pawpaw (7.9)>Orange (5.5)>Cassava (0.28). The sum of EDI for both adult and children exhibited similar trend with Cassava having the least value in both adult and children. Though metals showed low values of EDI, excessive consumption can have adverse effect in humans due to bioaccumulation in living system. Hazard Quotient (HQ) was highest for Pb...

Polycyclic aromatic hydrocarbon (PAHs) represent a class of organic compounds with carbon and hydrogen structure, having 2 or more fussed ring. recently the environmental protection agency (USEPA) included sixteen of these PAHs compounds in its list of persistent organic Pollutants (POPs). PAHs compounds are of public interest because it has a unique characteristic of being carcinogenic, mutagenic and tetratogenic and to this effect contributes to 3.1x10 incremental life time of cancer risk which is major cause to the increased cancer death in Nigeria. The most widely known carcinogenic PAHs is Benzo(a)Pyrene which is considered as a suitable biomarker for it’s occurrence in food and other environmental samples.But recently, the European Food Safety Authority (EFSA) suggest that benzo(a) pyrene alone should not be the most suitable biomarker of carcinogenic PAHs but rather a total number of 8 heavy molecular weight PAHs namely;benzo(a)anthracene, chrysene, benzo(a)pyrene, benzo(b)fl...

Assessment; Health; Permissible levels; Pollution; Hazard Quotient ABSTRACT: Oguta lake has experienced lots of oil spills and heavy metals and petroleum hydrocarbons could constitute fish contaminants. In order to assess the potential danger associated with consumption of fish from the lake by children and adults the current research was conducted. 6 g of each fish species from the lake were homogenized and divided into two portions. One was digested with aqua-regia while the other was extracted with hexane using a soxhlet extractor. Extracts were analyzed for heavy metal and hydrocarbons concentrations with AAnalyst Perkin Elmer 400 AAS and Buck 530 GC respectively. Data was interpreted with pollution and risk assessment models. Results revealed that except for Hg and Ni all other metals were below permissible levels by Food and Agricultural Organization (FAO). Estimated dietary intakes (EDI mg/kg day) were high in children (110.157) for C. spectaculurus to (25.212) for H. fossili...

With increasing population and human activities, dumpsites experience diverse sources of waste with potential radiation hazards. Ionizing radiations have often been overlooked amongst researchers in third world countries, hence, information in this regard is lacking. In this study, nine dumpsites within Imo State University (IMSU) grounds were assessed for radiation levels using Geiger Muller counter Tube Mullard type ZP 1481 with assisted scalar and stopwatch. After calibration, the instrument was placed one meter above ground level and counted rates recorded at 10 minutes interval for each location once in the morning, the afternoon, and the evening for seven days. Results reveal higher dose equivalents in some morning periods than in the afternoon and evening. Site ETF2 had the highest value of 0.69±0.08 mSv·yr, while Extension gate had lowest value of 0.56±0.01 mSv·yr. Compared to National Council for Radiation Protection maximum permissible level, these values are quite low. In...

This study assesses the physiochemical characteristics and heavy metals content of crude oil polluted soils and non-polluted soils from Ohaji/Egbema, Imo State. Soil samples were collected at depths of 0-30 cm at each sampling point and then analyzed using standard analytical methods. Data from the five areas were compared to standards for soils in Nigeria and in World Health Organization (WHO) data banks. The results obtained from the analysis showed an average pH of (4.88 ± 0.02 to 5.02 ± 0.04) for polluted soil and (6.57 ± 0.05 to 6.82 ± 0.03) for non-polluted soil, electrical conductivity (571 ± 1.1 to 592 ± 0.8 μS/cm) for oil polluted soil and (383 ± 0.5 to 415 ± 1.6 μS/cm) for non-polluted samples, moisture content (5.2 ± 0.2 to 9.1 ±0.1%) for polluted soil and (4.5 ± 0.1 to 4.7 ± 0.3%) for non-polluted soil samples. There was no significant difference in temperature and organic matter for both the polluted and non-polluted soil samples. The heavy metals analysis results showe...