Characteristic levels of heavy metals in canned sardines consumed in Nigeria

Samples of some popular brands of canned sardines in soybean oil in the Nigerian market were analyzed for levels of cadmium, lead, iron, cobalt, nickel, manganese, chromium, copper and zinc after wet digestion with acids by graphite furnace atomic absorption spectrophotometry. The mean concentrations for the metals in the different brands were as follows: cadmium 0.11–0.26 μg/g, iron 8.04–48.18 μg/g, cobalt 0.01–7.23 μg/g, nickel 0.04–3.26 μg/g, manganese 0.64–1.37 μg/g, chromium 0.01–0.10 μg/g, copper 0.10 μg/g and zinc 0.09–4.63 μg/g. Significant differences were observed in the heavy metal levels in the different brands of canned sardines except for copper and chromium. Cadmium, nickel and lead exceeded statutory safe limits.     

Assessment of Coastal Vulnerability Through the Use of GIS Tools in South Sicily (Italy)

This study assessed coastal erosion vulnerability along a 90-km sector, which included both erosional and accretionary beaches, and different levels of human occupation. Two aerial photogrammetric flights were used to reconstruct coastal evolution between 1977 and 1999. During this period, extensive accretion was recorded updrift of human structures at harbors and ports, e.g., Scoglitti (105.6 m), Donnalucata (52.8 m), and Pozzallo (94.6 m). Conversely, erosion was recorded in downdrift areas, with maximum values at Modica Stream mouth (63.8 m) and Point Castellazzo (35.2 m). Assessments were subsequently divided into four categories ranging from “high erosion” to “accretion.” Several sources were examined to assess human activities and land use. The latter was mapped and divided into four categories, ranging from “very high” to “no capital” land use. Subsequently, coastal erosion vulnerability was assessed by combining land use categories with recorded coastline behavior. Results showed “very high” to “high” vulnerability along 5.8% and 16.6%, respectively, of the littoral, while 20.9% and 56.7%, respectively, was found to exhibit “medium” and “low/very low” vulnerability. A very good agreement between predicted coastal vulnerability and coastal trend had been observed over recent years. Furthermore, several human structures and activities are located within the “imminent collapse zone (ICZ)” which reached maximum values of 17.5 m at Modica Stream and 13.5 m at Point Braccetto.     

A critical appraisal of PAH indices as indicators of PAH source and composition in Elelenwo Creek,southern Nigeria

The survey of polycyclic aromatic hydrocarbons (PAHs) and their relation to potential pollution sources were investigated in suspended particulate matter (SPM), surface waters, and sediments from Elelenwo Creek, southern Nigeria. Total PAH concentrations varied from 2,021.35 to 3,926.84 μg/kg dry weights in SPM and from 4,238.00 to 5,490.84 μg/kg dry weights in sediments. Furthermore, concentration levels of PAHs varied from 720.46 to 857.65 μg/l in the surface waters, which indicates that the aquatic ecosystem is polluted by PAHs. The 2, 3-ring PAHs were not dominant in SPM (34.73%), surface water (40.09%), and sediments (22.43%). While anthracene was more abundant, of the 2, 3-ring PAHs in SPM, the most abundant in the surface waters and sediments were fluorene and acenaphthylene. Four origin indices or concentration ratios of PAH isomer pairs were used to evaluate the suitability of these compounds as tracers to distinguish between the contamination arising from different sources. A critical appraisal of the PAH indices, therefore, suggested that biomass combustion is the major PAH source in the environmental matrices. Relative PAH patterns in the environmental matrices were also evaluated using principal component analysis, and were found to correlate with the PAH patterns of the different potential contamination sources.     

A socioeconomic and natural vulnerability index for oil spills in an Amazonian harbor: A case study using GIS and remote sensing

The coastal zone of the Brazilian state of Maranhão is an area characterized by a large variety of human activities and services, in particular in the Itaqui-Bacanga port complex (IBC). The IBC is an area prone to oil spills resulting from the processes of transportation, storage, and tank cleaning. The present study aimed to map the different physical environments adjacent to this complex and the socioeconomic profile of the local population that would be most vulnerable to this type of disaster. Vulnerability studies are essential as one of the first step in the development of an integrated coastal zone management. The variables analyzed in this study included geomorphological units, and the income, education, and dependence on fishing of the local population. The estimate of the vulnerability index was based on the relationships between these variables, which were used to generate a vulnerability map using GIS and the interpretation of high-resolution remote sensing, showing the areas of highest priority for intervention in the case of oil spills. The analysis of the natural and socioeconomic environments indicated that the areas of highest vulnerability correspond to the mangroves and the Vila Nova and Alto da Esperança neighborhoods, respectively. These neighborhoods have a direct relationship with fishing, and low levels of both income and education. By contrast, the lowest vulnerability was attributed to the coastal plateau and the central Anjo da Guarda neighborhood, which is occupied by residents with relatively high income and education, who do not depend on fishing.     

Spatial distribution of particulate matter (PM10) in Warri metropolis,Nigeria

This study examined the spatial distribution of particulate air pollution in the Warri metropolis. This was done to ascertain the differences between the distribution of particulate matter (PM10) in the urban area and the surrounding rural areas. To achieve this, the study generated data from field measurement of PM10 levels for the year 2003. Analysis of variance, the U-test, and simple regression statistical techniques were used to analyze the data. The major finding of the study was that the Warri metropolitan area is polluted with PM10 levels of over 126 μg/m³, which is 81% over the 70 μg/m³ threshold of the World Health Organization. However the built-up area of the Warri metropolis is 150% more polluted with PM10 particulates than the surrounding rural areas. While the traffic-clogged area of Enerhen, Jakpa, Deco, and Estate Junctions are the most polluted areas with levels of 151 μg/m³, traditional areas had the lowest levels of 128 μg/m³. The daily distribution of PM10 showed that Mondays were the most polluted days with levels of 145 μg/m³ and Fridays were the least polluted days with levels of 141.5 μg/m³ in the built-up area, whereas in the rural area Wednesdays were the most polluted days with levels of 57.1 μg/m³ and Sundays were the least polluted days with levels of 53.5 μg/m³. Mondays generally recorded the highest PM10 values because of the large amount of industrial operation, heavy vehicular traffic in the peak period, and increased commercial activities. The study also showed significant variation in the level of PM10 particulates within the urban areas of the Warri metropolis with a calculated F-value (3.29), which is greater than the critical F-value of 3.14 at the 0.05 significance level. It is therefore recommended that urban environmental management policy should be vigorously pursued to curb the adverse consequences of increased PM10 levels in urban areas of the Warri metropolis.     

Fish Species Used as Biomarker for Heavy Metal and Hydrocarbon Contamination for Cross River, Nigeria

Enhanced concentrations of Fe, Zn, Mn, Pb, Cu, Cd and total hydrocarbons (THC) determined in fish samples from the Cross River system, Nigeria have been associated with clinical defects (nausea, headache, hepatitis, body rashes) observed in coastal residents who are the major consumers of the fish species. Fish samples were collected from ten locations with varying degrees of exposure to human activities. Heavy metal concentrations in fish followed the sequence: Fe>Zn>Mn>Pb>Cu>Cd with the highest concentration of 243 g/g (Fe) wet weight occurring in Tympanotonus sp. Fe levels were significantly (P<0.001) higher than other metals analysed. The sequence in total hydrocarbon concentrations according to fish species was in the order of O. niloticus (55.1 g/g) > E. fimbriata > P. elongatus > Portonus sp. > C. nigrodigitatus > Tympanotonus sp. Generally, the demersal species showed a marked potential for tolerating high levels of heavy metals while the pelagic species showed preference for the accumulation of hydrocarbons. The degree of contamination depended on pollutant type, fish species, sampling location, trophic level and their mode of feeding. The persistent accumulation and tolerable potential of Tympanotonus, Portonus and P. elongatus suggest that they might be effectively utilized as self-integrating indicators for time-series monitoring of the rate of recovery of the impacted ecosystem by heavy metals. Possible sources of pollutant include leachates from municipal dumps, used crankcase oils from fluvial discharges (mechanic workshops) and occasional oil spills.     

沿海经济低谷区港口、城镇、产业联动发展研究述评

沿海地区港口、城镇、产业间有着息息相关的依存关系,三者联动发展的程度直接影响着沿海地区经济的发展.从港口区位、港口功能、港口与城镇空间联系、滨水区及海岸带开发的视角梳理了国外相关研究成果,从联动发展的理论和实证研究方面对国内大量文献进行了总结,并对未来的研究趋势进行评论与展望.     

Evidence of hydrocarbon contamination from the Burgan oil field, Kuwait: interpretations from thermal remote sensing data

The paper presents the application of thermal remote sensing for mapping hydrocarbon polluted sites. This has been achieved by mono-window algorithm for land surface temperature (LST) measurements, using multi-date band 6 data of Landsat Thematic Mapper (TM). The emissivity, transmittance and mean atmospheric temperature were used as critical factors to estimate LST. The changes in the surface emissivity due to oil pollution alter the apparent temperature, which was used as a recognition element to map out oil polluted surfaces. The LST contrast was successfully used to map spatial distribution of hydrocarbon pollution in the Burgan Oil field area of Kuwait. The methodology can be positively used to detect waste dumping, oil spills in oceans and ports, besides environmental management of oil pollution at or near the land surface.     

Evaluation of aquifer vulnerability and the protective capacity in some oil producing communities of western Niger Delta

Oil spills have become a major environmental hazard constituting serious social problems in Nigeria, especially in the oil producing communities. The spills contaminate the aquifer if the subsurface layers are not protected. Geoelectric technique of geophysical investigation has been used to evaluate the protective capacity of six oil producing communities: Oleh, Olomoro, Uzere, Afiesere, Ekakpamre and Uvwiamuge in the western Niger Delta. A total of 139 vertical electrical sounding (VES) using the Schlumberger electrode configuration were occupied in these communities. The longitudinal conductance maps delineated areas with poor (<0.1 mho), weak (0.1–0.19 mho), moderate (0.2–0.69 mho) and good protective capacity (0.7–4.9 mho). The study has shown that the protective capacity of most parts of the communities studied is poor with Uvwiamuge and Ekakpamre communities not protected hence the aquifer in these oil producing communities are vulnerable to contamination by hydrocarbon in the event of pollution. Hence proper environmental protection measures have been suggested to safeguard the aquifer from pollution by hydrocarbon in the event of spillage.     

Physiological responses of Avicennia marina seedlings to the phytotoxic effects of the water-soluble fraction of light Arabian crude oil

Stomatal behavior, growth performance and the accumulation of polynuclear aromatic hydrocarbons (PAHs) were evaluated in seedlings of the mangrove Avicennia marina (Forssk.) Vierh., treated with a water-soluble fraction (WSF) of Abu-Dhabi light Arabian crude oil through foliar spraying or soil application.Irregular stomatal behavior and weak stomatal control over transpiration were observed during the first 24 hours, where stomatal resistances of plants sprayed with 150 and 300 g PAHs plant^–1 were significantly lower than that of the control plants. After six weeks, all treated plants showed no significant difference in their relative growth rate (RGR) or in the net assimilation rate (NAR) compared with the control plants.Tri-aromatic hydrocarbons were the most accumulated in tissues of the treated plants. Penta- and hexa-aromatics, on the other hand, were undetectable in the WSF and consequently in the treated plants. A linear relationship was observed between the dose applied to plants and the amounts of tissue accumulated PAHs (r ²=0.515 for soil application and r ²=0.984 for foliar spray). In plants sprayed with 300 g PAHs plant^–1, the total PAHs accumulated were more than that accumulated in plants treated through soil application.These findings suggest that: aqueous extraction of crude oil tends to signify the percentage of the low molecular weight PAHs, e.g. naphthalene, to the total PAHs; disturbed stomatal behavior in the first day of the treatment may be due to the venting of the volatile low molecular weight aromatic hydrocarbons (e.g. benzene, toluene, and xylenes) through the stomata; and uptake of water-soluble hydrocarbons by plants is equally possible through both of the root system and the foliage. The ecological implications of these finding are discussed in relation to oil pollution of mangrove stands under field conditions.     

三峡库区典型次级支流表层沉积物中PAHs的分布特征及来源分析

本文表征了三峡库区典型次级支流(梁滩河)表层沉积物中18种多环芳烃(PAHs)的浓度,并对其分布特征和污染来源进行了探讨。18种PAHs的总浓度(∑18 PAHs)范围为198.5～4349 ng/g-dw(干重),平均浓度为1441ng/g,中值为1160 ng/g。与其他地区沉积物污染情况相比,梁滩河沉积物中PAHs浓度处于中等偏低的污染程度,支流污染程显著高于干流,流经城镇的右支污染程度显著高于流经农村或人口较少的左支和主干流。大部分采样点以高环(4～6环)PAHs污染为主。PAHs源解析结果表明,梁滩河表层沉积物中PAHs污染以燃烧源为主,主要源于化石燃料和生物质的不完全燃烧。沉积物中苯并[a]芘的毒性当量因子(TEF)值为39.38～384.37 ngTEQ/g,平均值110.94 ngTEQ/g。生态风险评价的结果表明,右支流的两个采样点R3和R4点沉积物中PAHs可能存在生物负效应影响,R4点的高风险可能与附近白市驿机场污染有关。     

Contaminants evaluation of Marais des Cygnes National Wildlife Refuge in Kansas and Missouri,USA

At the new Marais des Cygnes National Wildlife Refuge in Linn County, Kansas, and Bates County, Missouri, USA, we evaluated long-lived contaminants before acquisition of the land for the refuge. We sampled sediments at 16 locations and fish at seven locations. The samples were analyzed for metals and for chlorinated hydrocarbon compounds. Selected sediment samples also were analyzed for aliphatic hydrocarbons. Arsenic concentrations in sediment samples from six locations were elevated compared to US norms, but arsenic was not detected in any fish composite. Mercury concentrations in largemouth bass from two locations were comparable to the 85th percentile concentrations in nationwide fish collections. Most sediment concentrations of other metals were unlikely to have detrimental effects on biota. No chlorinated hydrocarbons were detected in any sediment sample. Chlordane compound concentrations in fish composites from two sites at the eastern end of the sampling area were 0.127 and 0.228 μg/g wet weight, respectively, which are high enough to cause concern. Most aliphatic hydrocarbons detected were found at low concentrations and probably were natural in origin. We concluded that there are no serious contaminants concerns within the project area, but past use of arsenical pesticides may mean a legacy of elevated soil arsenic levels in parts of the area and some use of banned pesticides such as chlordane and DDT likely is still occurring near the refuge.     

Heavy metal distribution in crab (<Emphasis Type="Italic">Callinectes amnicola</Emphasis>) living on the shores of Ojo Rivers,Lagos, Nigeria

Crab samples, both male and female specie, were purchased from fishermen at the Ojo Rivers, Lagos, Nigeria. The samples separated into abdomen, muscle tissue, and thorax were oven dried at 80°C for 3 days. The dried samples were then pulverized in a clean acid-washed mortar and pestle. Approximately 1.00 g each of the pulverized samples was weighed and Zn, Cr, Pb, and Cd were determined in the solution of the aqua regia digested samples by means of AAS (Buck Scientific 210 GVP model). The results obtained showed Zn metal to be consistently higher in all the female parts compared to the male with values of 12.92 ± 3.65 μg/g to 16.03 ± 1.08 μg/g and 9.33 ± 1.77 μg/g to 15.75 ± 1.02 μg/g, respectively. Mean values of 0.39 ± 0.09 μg/g and 0.22 ± 0.02 μg/g cadmium were found in the abdomen and tissue of the male crab as against 0.35 ± 0.07 μg/g and 0.17 ± 0.07 μg/g in the female crab. The tissues of both species have comparable value of chromium. Lead was below the detection limit of 0.05 μg/g in the tissues of male crab but the female tissue contained 0.83 ± 0.13 μg/g and in other parts identified, lead was consistently higher than the 2.00 μg/g permissible level of WHO in foods. A simple pair t-test did not demonstrate any significant difference in the distribution of metals between the male and female crabs. The coefficient of variation (CV) calculated for each metal with respect to the studied parts showed Pb to be widely distributed (56.23–89.54%) while Cr did not vary widely (4.17–8.20%).     

PETROLEUM HYDROCARBONS IN URBAN RUNOFF1

ABSTRACT: Estimates were made of petroleum hydrocarbon pollution loadings reaching the Delaware Estuary by determining storm event loadings of hydrocarbons from four storm sewers, draining areas of different land uses. Although refinery effluents constituted the largest source of petroleum pollution in 1975, it appears that after completion of currently required treatment processes urban runoff will be the largest remaining source of petroleum pollution. The petroleum in urban runoff resembles used crankcase oil in composition and contains toxic chemicals such as polynuclear hydrocarbons. Further research is clearly desirable. Remedial programs to control such pollution may be warranted on the basis of information now available.     

Effect of the Prestige oil spill on salt marsh soils on the coast of Galicia (northwestern Spain)

At four estuarine sites on the coast of Galicia (northwestern Spain), all of which were affected by the Prestige oil spill, soil samples were taken from polluted and unpolluted areas and their petroleum hydrocarbon contents, heavy metal contents, and other chemical and physical characteristics were measured. Oil pollution altered both chemical and physical soil properties, aggregating soil particles in plaques, lowering porosity, and increasing resistance to penetration and hydrophobicity. The chromium, nickel, copper, iron, lead, and vanadium contents of polluted soils were between 2 and 2500 times higher than those of their unpolluted counterparts and the background concentrations in Galician coastal sediments. In the cases of Cr, Cu, Ni, Pb, and V, their origin in the polluting oil was corroborated by the high correlation (r >/= 0.74) between the concentrations of these metals and the total petroleum hydrocarbon (TPH) content of the polluted soils. Soil redox potentials ranged from -19 to -114 mV in polluted soils and 112 to 164 mV in unpolluted soils, and were negatively correlated with TPH content (p < 0.01). The low values in the polluted soils explain why the soluble fractions of their total heavy metal contents were very small (generally less than 3%, and in many cases undetectable).     

Spatial and Temporal Effects of Port Facilities Expansion on the Surface Area of Shallow Coral Reefs

There is a close relationship between ports and reef areas, mainly because reefs provide protection to vessels against extreme weather events like storms and hurricanes. This historical relationship has generated severe impacts on reef ecosystems. In order to identify the main impacts from the construction of port facilities in shallow coral reef areas, we analyzed and described the effects of land reclamation and coastal structure construction associated to port growth throughout a century in the Sistema Arrecifal Veracruzano National Park, Mexico. We used aerial photographs and maps of the nineteenth and early twentieth century to assess the impacts caused by port expansion activities on shallow coral reefs. Three types of impacts were identified: (a) direct reef area loss caused by landfills and perpendicular coastal structures construction leading to the loss of nearly 50 % of the fringing reef near to the port; (b) fragmentation in short- and medium-term scale, which affects two fringing reefs, and (c) long-term modification of coastal dynamics leading to sedimentation and loss of a complete reef area. On the eve of a new expansion of Veracruz Port, we used the New Port Project Plan, long-shore net drift geomorphic indicators and the port impact typology from the 100-year period assessment to evaluate a possible future scenario. The scenario describes how the new expansion project will repeat the three types of impacts affecting a whole reef area, which is currently part of the National Park.     

Physicochemical Characteristics and Pollution Indicators in the Intertidal Zone of Kuwait: Implications for Benthic Ecology

/ The coastal environment of Kuwait has been under considerable stress since the onset of the oil era in the late 1950s and early 1960s. Oil, sewage, and industrial pollution were believed to be the main environmental problems in the coastal zone. The huge oil spill and destruction caused by the Gulf War further complicated those problems. In this article, the temperature, pH, salinity, and total dissolved sulfide (TDS) of the interstitial water in the intertidal zone and the water content and total organic carbon (TOC) of the intertidal sediment were investigated. The purpose of the study was to understand the effect of the physicochemical characteristics on the intertidal benthic ecology and to identify the level and sources of organic pollution in the intertidal zone. The study results indicated that the prevailing harsh environmental conditions, especially high temperature and salinity, restricted benthic fauna diversity and led to the development of a fragile intertidal ecosystem. The fauna inhabiting the intertidal zone was dominated by a few species probably living at their limit of tolerance. Organic pollution was evident mainly in Sulaibikhat Bay and to a lesser extent in Kuwait City waterfront and Shuaiba coast in the south. The pollution was attributed mainly to land-based sources such as the occasional discharge of raw sewage through stormwater outlets, the direct oil spillage, and industrial effluents from refineries, oil terminals, and petrochemical plants. Quantitative analysis was inconclusive in establishing a significant correlation between the chemistry and composition of the benthic fauna. However, close examination of sites with high TOC and TDS concentrations indicated that the benthic fauna in those sites was showing evidence of degradation. A number of strategies were recommended to ensure protection and sustainable management of the coastal environment.KEY WORDS: Intertidal environment; Pollution; Total organic carbon; Dissolved sulfide; Interstitial water; Benthic fauna     

Petroleum hydrocarbons and limiting nutrients in <Emphasis Type="Italic">Macura reptantia</Emphasis>, <Emphasis Type="Italic">Procambarus clarkii</Emphasis> and benthic sediment from Qua Iboe Estuary,Nigeria

The levels of total petroleum hydrocarbons in two commonly consumed benthopelagic shellfishes, Macura reptantia and Procambarus clarkii, harvested from benthic sediment of Qua Iboe Estuary were determined using a gas chromatography with flame-ionization detector. Seventy-two (72) samples each of benthic sediment and the shellfishes were collected monthly between June 2003 and February 2004 covering the peak periods of the wet and dry seasons. Concentrations of hydrocarbons were highly variable and ranged between 5.00 and 232.00 μg/g dry weight of benthic sediment, 3.05 and 11.30 μg/g dry weight of M. reptantia, 1.62 and 9.00 μg/g dry weight of P. clarkii. Pearson’s correlation analysis of total hydrocarbon concentrations in subtidal sediments with levels in the fauna species yielded positive significant (P < 0.05) correlations in M. reptantia (r = 0.737) and P. clarkii (r = 0.924). This is indicative of a long term and chronic accumulation of hydrocarbons in the estuarine ecosystem, reflecting the potential for exposure of the resident biota and the risk to human health.     

浅析含油污泥处理中石油烃控制指标

石油烃含量是含油污泥处理中必不可少的重要控制指标。文章分析了含油污泥中石油烃组成及主要污染控制要求,介绍了国内外含油污泥处置对石油烃含量的控制现状;依据危险废物鉴别标准的相关规定,以及对原油中芳香族化合物及其多环芳烃含量的研究成果,对采用石油烃指标进行危险废物鉴别做了推论计算。结果认为:含油污泥等固体废物及其处理残余物的石油烃含量≤0.25%,不属于危险废物;石油烃含量介于0.25%～1.7%时,其是否属于危险废物,最终需要进行危险废物鉴别而确定;石油烃含量1.7%,则属于危险废物。     

Mitigating Industrial Pollution Along the Atlantic Coast of Cameroon: An Overview of Government Efforts

Summary This paper presents an overview of the initiatives that have been formulated by the government of Cameroon to address the problem of industrial pollution. It also prescribes robust recommendations that could be employed to save the Atlantic coast of Cameroon from industrial pollutants. After the participation of Cameroon in the Earth Summit in Rio de Janeiro in 1992, the government took a significant step to overhaul its institutional framework, legal framework and policy framework vis-à-vis the regulation of industrial pollution. Under the auspices of the United Nation Industrial Development Organisation (UNIDO), the Gulf of Guinea Large Marine Ecosystem Project aimed at sustaining the health of the Atlantic coast of Cameroon by ensuring treatment of industrial wastes, oil spills, sewage and heavy metals was implemented (1995–1999). Based upon careful analysis, however, the paper argues that these efforts have had little or no discernable impacts and that industrial activities along the Atlantic coast of Cameroon are still a major threat to safety, health and the environment. With a considerable number of hurdles that still persist, sufficient environmental improvement in industrial pollution along the Atlantic coast of Cameroon is far-fetched. Nevertheless, the paper concludes that marked environmental improvement can be obtained if: (i) competent personnel are appointed in ministries that play an active role in mitigating industrial pollution (ii) research partnerships are forged with local universities (iii) industrial machinery and equipment are improved (iv) inter institutional conflicts are addressed (v) a more collaborative forum between stakeholders is established (vi) adequate monitoring is instituted. The provisions of this paper form the foundation of an ongoing research being conducted by the authors at Brandenburg University of Technology, Cottbus, Germany.