Levels of Organochlorine Pesticides in Brackish Water Fish from Niger River, Nigeria.

Investigation of the levels of organochlorine pesticides (OCPs) in fish samples was carried out to assess the contamination status of Niger River. Ten different brackish water species of fish (6 samples for each, making a total of 60) were purchased from landing sites at the Delta area of Niger River. These were Drapane africana, Mochokus niloticus, Chrysichthys nigrodigitatus, Pristipoma jubelini, Vomer septapinis, Pseudotolithus senegalensis, Mugil cephalus, Pseudotolithus elongatus, Sphyraena piscatorum, and Lutjanus goreensis. OCPs were determined using standard methods. Certified reference standards from Accustandard USA were used for the instrument calibration and quantification of OCPs. Twenty OCPs, namely, α-HCH, ß-HCH, γ-HCH, δ-HCH, endrin, endrin aldehyde, endrin ketone, heptachlor, heptachlor epoxide, aldrin, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, methoxychlor, α-chlordane, γ-chlordane, DDE, DDT, and DDT, were identified/quantified using Gas Chromatography (GC) (Hewlett Packard GC 5890 series 11 with electron capture detector). Confirmation was done using Shimadzu GCMS QP2010. The highest concentration of ∑OCPs in the brackish fish samples of the Niger River, 4302±2066 µg/kg fresh weight, with a range of 2237-6368 µg/kg, was detected in Drapane africana, while the lowest concentration, 2320±876.4, with a range of 1006-3288 µg/kg, was found in Mochokus niloticus. The concentration of total OCP compounds varied markedly amongst the different fish species. The guideline value of 2000 µg/kg fresh weight by WHO/FAO was exceeded and therefore implied potential harmful effects on humans. Since contamination of the fish samples was an indication of contamination of the river, the quality of the water for public water supply should be of concern; and therefore further monitoring is suggested.

Inventory and substance flow analysis of polybrominated diphenyl ethers in the Nigerian transport sector-end-of-life vehicles policy and management.

Recently, certain polybrominated diphenyl ethers (PBDEs) have been listed as persistent organic pollutants (POPs) in the Stockholm Convention. In this study, a preliminary material and substance flow analysis of commercial pentabromodiphenyl ether (c-PentaBDE) was conducted for motor vehicles-a major use sector for POP-PBDE in polyurethane (PUR) foam-for Nigeria. The methodology of the Stockholm Convention PBDE inventory guidance was used for the calculation of c-PentaBDE. Material/substance flow analysis was conducted applying the STAN software. The time frame for this analysis was 1980-2010, considering that this was the period when POP-PBDE-containing vehicles were largely imported into Nigeria.It is estimated that the approximately 19 million passenger cars imported from 1980 to 2010 contained ca. 270 t of POP-PBDEs in ca. 401,000 t of PUR foam. A major share of cars from the USA and only a small share of cars from Europe and Asia were impacted. This simplified material and substance flow of PUR foams and POP-PBDEs in motor vehicles demonstrated the potential for environmental/human contamination and pollution of recycling/reuse for Nigeria and other developing countries.The study developed the first preliminary inventory of end-of-life vehicles for Nigeria, following which the environment ministry has taken up the important issue of end-of-life vehicles management. Considering that a range of other pollutants are contained in vehicles (e.g. heavy metals, flame retardants, PCBs, chlorofluorocarbons, hydrofluorocarbons and waste oil), this initiated activity should finally lead to an integrated management of pollutants and resources from the transport sector.

Polychlorinated biphenyls (PCBs) in River Niger, Nigeria: Occurrence, distribution and composition profiles.

Contamination of rivers with persistent organic pollutants (POPs) is an issue of current global concern. Polychlorinated biphenyls (PCBs) are POPs with origin from commercial, incineration and industrial sources. Hence, there is a need for monitoring their occurrence and distribution in the environment. This study assessed the occurrence, distribution and composition profiles of PCBs in River Niger, Nigeria. Surface and bottom water samples were collected in consecutive quarters for a period of 2 years, covering the beginning and end of the rainy seasons and the dry seasons, from five locations (Gurara, Lokoja, Onitsha, Brass and Nicolas) along River Niger. A total of 240 water samples were collected using a Van Dorn water sampler. EPA method 3510c was used with slight modifications for sample preparation and analysis. The PCBs were analysed using a Hewlett Packard GC 5890 Series 11 with electron capture detection, and confirmation was made using a Shimadzu GCMS QP2010. The higher molecular weight marker PCBs (∑CB 138, 153 and 180) were more dominant than the lighter homologues (∑CB 28, 52 and 101), while commercial sources Co-PCBs (80.8 ± 61.7 to 288.3 ± 102.0 ng L-1) were more dominant than the incineration sources (34.9 ± 3.82 to 75.5 ± 65.2 ng L-1). The POPs load in River Niger water varied in both time and space. In surface water of the River Niger, ∑PCBs were higher during the rainy season, as a result of storm run-off from land-based sources. In the Brass and Nicolas Rivers during the dry season, the ∑PCBs were higher during low tide. There was no noticeable pattern during the rainy season. It may be concluded from this study that the water of River Niger is not good for human consumption or abstraction of water from the river for drinking water treatment.

Selected persistent organic pollutants (POPs) in water of River Niger: occurrence and distribution.

This study assessed the levels and distribution of selected persistent organic pollutants (POPs) in water of River Niger. The selected POPs of interest were organochlorine pesticides (OCPs). Fifteen representative sites along River Niger: three each from Gurara River (tributary) in Niger State, Lokoja (confluence) in Kogi State, Onitsha in Anambra State, Brass and Nicolas Rivers (tributaries) in Bayelsa State were selected for sampling quarterly over a 24-month period. A total of 240 surface and bottom water samples were collected using Van Dorn water sampler in the eight quarters of 2008-2009. At the Delta locations where tidal effects take place, high- and low-tide water samples were taken as compared to surface and bottom at the River Niger locations. For sample extraction, EPA method 3510c was employed with slight modifications. Certified reference standards from Accustandards USA was used for the instrument calibration and quantification of OCPs. The extracted samples were subjected to gas chromatography (GC/ECD) for identification/quantification. And Shimadzu GCMS QP2010 was used for confirmation. Chlordane, endosulfan, endrin and DDT metabolites were very prominent in the water samples, compared to HCH, dieldrin, and isomers which occurred at lower concentrations. The sequence in the concentration of the organochlorine pesticides were ∑chlordane > ∑DDT > ∑endosulfan > ∑endrine > ∑dieldrin > ∑HCH. The highest concentration of ∑OCPs in water samples of River Niger, 1138.0 ± 246.7 ng/L, with range 560.8-1629 ng/L was detected at Onitsha location, while the lowest concentration, 292.6 ± 74.9, with range 181-443.0 ng/L was detected at Nicolas River. Levels of OCPs in a larger percentage of the samples exceeded guidelines and therefore hold potential harmful effects on benthic fauna, fish, and man. Abstraction of water from the River for drinking water treatment should be discouraged. Because of the potential danger, this presents, continuous monitoring of the water body and if possible remediation, determination of the sources of the POPs is therefore very necessary.

Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in e-waste plastic in Nigeria.

Plastics from cathode ray tube (CRT) casings were sampled in Nigeria and analysed for their polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/F) content. PBDD/Fs, consisting mainly of PBDFs, were detected in BFR containing plastic with a median (mean) concentration of 18,000 ng/g (41,000 ng/g). The PBDD/Fs levels were highest in samples containing PBDEs, but the levels of PBDFs were two orders of magnitude higher than the levels reported in the technical PBDE mixtures and where frequently exceeding 1000 µg/g of PBDE content. These higher levels are likely to arise from additional transformation of PBDEs during production, use, recycling, or storage, but the processes responsible were not identified in this study. PBDD/Fs in CRT casings containing1,2-bistribromophenoxyethane (TBPE) were dominated by tetrabrominated dibenzo-p-dioxin (TBDDs) with concentrations around 10 µg/g of the TBPE content. The PBDD/Fs in CRT casings containing tetrabromobisphenol A (TBBPA) were found at concentrations around 0.1 µg/g of TBBPA levels. Casings treated with TBPE or TBBPA often contained PBDEs (and PBDF) as impurities-probably originating from recycled e-waste plastics. It was estimated that the 237,000 t of CRT casings stockpiled in Nigeria contain between 2 and 8 t of PBDD/Fs. The total PBDD/F contamination in polymers arising from total historic PBDE production/use is estimated in the order of 1000 t. TEQ values of CRT samples frequently exceeded the Basel Convention's provisional low POPs content of 15 ng TEQ/g. Due to the significant risks to health associated with PBDD/Fs, more detailed studies on the exposure routes from PBDD/Fs in stockpiles are needed.

Toxicity characterization of waste mobile phone plastics.

Waste plastic housing units (N=60) of mobile phones (of different models, and brands), were collected and analyzed for lead, cadmium, nickel and silver using atomic absorption spectrophotometry after acid digestion using a 1:1 mixture of H2SO4 and HNO3. The mean (+/-S.D.) and range of the results are 58.3+/-50.4mg/kg (5.0-340mg/kg) for Pb, 69.9+/-145mg/kg (4.6-1005mg/kg) for Cd, 432+/-1905mg/kg (5.0-11,000mg/kg) for Ni, and 403+/-1888mg/kg (5.0-12,500mg/kg) for Ag. Approximately 90% of the results for the various metals were < or =100mg/kg. Results greater than 300mg/kg were generally less than 7% for each metal and could be attributed to exogenous contamination of the samples. These results suggest that there may not be any immediate danger from end-of-life (EoL) mobile phone plastic housing if appropriately treated/managed. However, considering the large quantities generated and the present low-end management practices in most developing countries, such as open burning, there appears a genuine concern over the potential for environmental pollution and toxicity to man and the ecology.

Modelling waste generation by the telecom sector in Nigeria: the grey side of the impressive outing.

Since the introduction of digital mobile technology into Nigeria in 2001, there has been a phenomenal improvement in mobile subscription, service delivery and in the overall penetration of mobile telecommunication into rural areas in the country. For instance, the country's teledensity increased from less than 1% in 2001 to about 25% in 2006 - an increase of more than 3000%. The aim of this paper is to predict improvements in telephone penetration and waste generation by the Nigerian telecommunications sector. This was achieved by regression analysis of available data on telephone subscription in the country. Our estimations indicate that an average of 3 million phones will be retired annually in the country. Considering an economic phone life of 4 years, the over 32 million phones, (weight estimated at about 3200 tons) in use in 2006 would be at their end-of-life (EoL) by 2010. This volume of waste may contain up to 1800 tons of waste plastics, 15 tons of lead and 124 tons of copper. Our derived regression equation also indicates that mobile phone penetration in the country would be about 40% by 2010. This implies that over 55 million mobile phones would be in use by 2010. The grey side of this impressive statistics is that waste generation by the telecommunications sector will also follow this trend. This paper also highlights the need to introduce a framework for the effective management of waste from this sector considering the toxicity of some of the components of mobile phones and accessories and the prevailing inappropriate disposal practices for such potentially 'toxic' materials.

Estimating sectoral pollution load in Lagos by Industrial Pollution Projection System (IPPS).

Sensitivity to environmental issues brought about increasing pressure from local community, groups, environmental organizations and government regulators on industries to reduce their pollutant emissions. In this study, Industrial Pollution Projection System (IPPS), which was developed by the Infrastructure and Environment Team of the World Bank, was used to estimate pollution load in ton/yr (with respect to employment) of industrial sectors in Lagos. The IPPS was developed to exploit the fact that the scale of industrial activity, its sectorial composition, and the process technologies, employed in production, heavily affect industrial pollution. Available data, from Manufacturer's Association of Nigeria (M.A.N.) for the years 1997-2002 was used for the estimation. From the cumulative ranking of the pollution load (ton/yr) estimate to all media (i.e. air, land, and water), Chemical and Pharmaceutical (CPH) sector is the highest polluting sector, followed by Basic Metal (BML), Domestic and Industrial Plastics (DIP), and Food, Beverage and Tobacco (FBT) sectors. Some of these sectors have the highest number of employees, and also appeared as the most polluting sectors in Lagos.

The challenge of electronic waste (e-waste) management in developing countries.

Information and telecommunications technology (ICT) and computer Internet networking has penetrated nearly every aspect of modern life, and is positively affecting human life even in the most remote areas of the developing countries. The rapid growth in ICT has led to an improvement in the capacity of computers but simultaneously to a decrease in the products lifetime as a result of which increasingly large quantities of waste electrical and electronic equipment (e-waste) are generated annually. ICT development in most developing countries, particularly in Africa, depends more on secondhand or refurbished EEEs most of which are imported without confirmatory testing for functionality. As a result large quantities of e-waste are presently being managed in these countries. The challenges facing the developing countries in e-waste management include: an absence of infrastructure for appropriate waste management, an absence of legislation dealing specifically with e-waste, an absence of any framework for end-of-life (EoL) product take-back or implementation of extended producer responsibility (EPR). This study examines these issues as they relate to practices in developing countries with emphasis on the prevailing situation in Nigeria. Effective management of e-waste in the developing countries demands the implementation of EPR, the establishment of product reuse through remanufacturing and the introduction of efficient recycling facilities. The implementation of a global system for the standardization and certification/labelling of secondhand appliances intended for export to developing countries will be required to control the export of electronic recyclables (e-scarp) in the name of secondhand appliances.

Landfill leachate-induced toxicity in mice.

Microbial, plant and studies in aquatic animals have shown that landfill leachate is toxic. However, more information about its effects in terrestrial animals is required. As a part of ongoing research into the toxic effects of landfill leachate in Nigeria, we evaluated the acute effects of raw and simulated leachates from Abadina, Orita-Aperin and Oworonsoki dump sites, all in Southwest Nigeria, in mice. Raw leachates were obtained directly from the dumps while the simulated leachates were obtained from the solid wastes in the laboratory by using the ASTM method. The samples were designated Abadina raw leachate (ARL), Orita-Aperin raw leachate (OARL) and Oworonsoki raw leachate (OWRL); and Abadina simulated leachate (ASL), Orita-Aperin simulated leachate (OASL) and Oworonsoki simulated leachate (OWSL). Their physico-chemical properties were determined in accordance with standard analytical methods. Young male mice (12-15 wk) weighing 24-31 g were exposed to 1%, 5%, 10%, 25%, 50% and 100% concentrations of each test samples for 5 consecutive days and were observed for a period of 96 h for toxic response. Mortality recorded at different times for each sample at the various concentrations was mostly within the last 48 h of the exposure period. The LC50 obtained are 100% for both ARL and OARL, and 50% for OWRL; and 83.50% and 50% for ASL and OWSL, respectively. It was indeterminate for OASL. Apart from this, other toxic effects like weight loss, sluggishness, loss of hair and reduced food intake were observed. The investigated samples were ranked as OWRL > OWSL > ASL > OARL > ARL > OASL. The observed effects were due to the toxic constituents present in the leachate samples. This suggests that the mixtures have the potential to cause harmful effect to public health and our environment through seepage into ground or surface water.

Residues of organochlorine pesticides in fruits, vegetables and tubers from Nigerian markets.

Residue levels of organochlorine pesticides have been determined in raw fruits, vegetables and tubers from markets in Nigeria. In the fruits, total HCH, aldrin and total DDT were detected in 77, 38 and 30% of all samples, respectively. In the vegetables, total HCH, HCB, total DDT and aldrin were detected from 95, 53, 50 and 30%, respectively, of all samples. Aldrin + dieldrin, total HCH, and total DDT were detected from 98, 79 and 49%, respectively, of all tuber samples. Other pesticides were below their detection limits. The average levels were generally low and none were above the FAOs maximum residue limits.

Review of heavy metals in the African aquatic environment.

Data were compiled from selected heavy metal studies in both freshwater and marine ecosystems from the major African subregions, Northern, West and Central, Eastern, and Southern Africa. The concentrations of heavy metals were compared between different environmental compartments (water, sediments, fauna, and flora), between the different African subregions and with data from other areas in the world. Despite the scarcity of the existing information on Africa, some conclusions could be drawn: Metal concentrations in organisms were generally below WHO limits except for some localized sites, mostly with increased lead levels. There were no significant differences between inland water and coastal animals, but shellfish had higher concentrations of most metals than finfish. For aquatic plants the heavy metal levels were higher in inland waters. Compared to more industrialized regions and with the exception of some hot-spot sites, the concentrations of heavy metals in African aquatic systems were low and close to natural background levels. Nevertheless, in view of the expected increase in urbanization and socio-economic activities in Africa, sources and quantities of heavy metal discharges to aquatic environments have to be identified. Also, pollution control measures should be formulated in each country.

Nutrient composition of milk produced by mothers of preterm infants in Nigeria.

Nutrient composition was determined in breast milk obtained by manual expression from 12 mothers who delivered prematurely (mean 32 weeks) and 15 mothers who delivered at term (mean 39.4 weeks), on days 3, 7, 14, 21 and 28 postpartum. Complete 24-hour milk expressed by five term mothers and seven preterm mothers on days 7, 14, 21 and 28 lactational ages was also recorded. In both preterm and term mothers' milk, lactose and fact concentrations increased with lactational age, while protein and mineral concentrations decreased. The preterm mothers' milk contained higher concentrations of protein, fat and minerals and lower concentrations of lactose than term mothers's milk. The fat and caloric density of milk of the mothers in this study, who were mostly of low social class, was lower than that reported from Western countries. The implication of this finding for feeding premature infants in developing countries is discussed.