Health Risk Assessment of Plasticizer in Wastewater Effluents and Receiving Freshwater Systems

Health risk assessment of plasticizer in wastewater effluents and receiving freshwater systems Luqman M (ed): Recent Advances in Plasticizers Rijeka, Croatia: InTech Online Publishers, 2012, pp 191-212, ISBN 978-953-51-0363-9A variety of human activities e.g. agricultural activities, urban and industrial development,mining and recreation, significantly alter the quality of natural waters, and changes the water use potential (Spinks et al., 2006; Madungwe and Sakuringwa, 2007). The key to sustainable water resources is, therefore to ensure that the quality of water resources are suitable for their intended uses, while at the same time allowing them to be used and developed to a certain extent. Water quality management, therefore involves the maintenance of the fitness for use of water resources on a sustained basis, by achieving a balance between socio-economic development and environmental protection. Approximately 40 000 small-scale farmers, 15 000 medium-to-large-scale farmers, 120 000 permanent workers, and an unknown number of seasonal workers are involved in irrigation farming, which consumes approximately 51 to 61 % of South Africa’s water on some 1,3 million hectares (Backeberg, 1996; Blignaut and Heerden, 2008). Irrigation farming contributes 25 to 30 % of South Africa’s agricultural output. Agriculture is crucially important to the basic food security of the poor, who constitute 40 % of the population of 42 million, and who are overwhelmingly concentrated in rural areas and (peri-) urban townships (Blignaut and Heerden, 2008). Like many countries in the world, water scarcity is becoming a major problem in South Africa (Marcucci & Tognotti, 2002; Oweis & Hachum, 2009; Komnenic et al., 2009) as dams serving communities with drinking water and water for daily household use, have been less than 30% full in recent years (Qiao et al., 2009; Malley et al., 2009). River water, in combination with groundwater, effluents from wastewater treatment plants, is considered a suitable alternative as a utilisable and potable water source (Blignaut and Heerden, 2008). To complement scare water resources, there has been increase in the number of wastewater facilities in many countries. This is to forestall the outbreak of environmental pollution and spread of diseases, remove conventional pollutants (such as ammonia and phosphate), and to maintain and restore the biologic integrity of surface waters (Wang et al., 2005; Sun et al., 2008)

METAL CONTENTS IN FISH AND CRUSTACEANS FROM BRACKISH, FRESHWATER AND MARINE SYSTEMS IN SOUTH-WESTERN NIGERIA

Prikazanom studijom istražene su koncentracije elemenata u tragovima u mišićima ili cijelim uzorcima 37 riba i rakova sakupljenim mrežama stajačicama u slatkovodnim (Olomore), morskim (Eti osa) i boćatim vodama nigerijskih država Ogun i Lagos, od lipnja do kolovoza 2013. Elementi u tragovima utvrđeni su pomoću ICP-MS nakon digestije u mikrovalnom autoklavnom sustavu. Razultati su otkrili kako je opći trend elemenata u tragovima u uzorkovanim ribama i rakovima morski > boćati > slatkovodni. Uzimajući u obzir sve uzorke, 16,2% i 13,5% prekoračilo je granice bakra i cinka (20 µg g-1 i 30 µg g-1), propisane od strane Europske Unije, dok je 71%, 50%, 79% morskih, slatkovodnih i boćatih uzoraka prekoračilo granicu od 48mg željeza na 60kg čovjeka, koju je postavila FAO/WHO. Uzorci su premašili prihvatljivu granicu postavljenu od strane FAO/WHO, čime je dokazano kako je potrebno uložiti trud u monitoring otpadnih voda koje se ispuštaju u otvorene vode Nigerije.Present study investigated trace element concentrations in either muscles or whole samples of 37 finfish and crustaceans harvested with gillnet from fresh (Olomore), marine (Eti osa) and brackish (Lekki Lagoon) waters of Ogun and Lagos states, Nigeria between June and August 2013. Trace elements were determined using ICP-MS after digestion with a microwave autoclave system. The results revealed that the general trend of trace elements in the sampled finfish and crustaceans was marine > brackish > freshwater. If all the samples are considered, 16.2% and 13.5% exceeded the 20 µg g-1 and 30 µg g-1 limits for Cu and Zn, respectively, as set by the European Union, while 71%, 50%, 79% of marine, fresh and brackish samples, respectively, exceeded the limit of 48 mg Fe per 60 kg person as set by FAO/WHO. In addition, samples exceeded the acceptable limit set by WHO/FAO, thus adequate efforts should be placed on the monitoring of effluents that are being discharged into open water bodies in Nigeria

Metal contents in fish and crustaceans from brackish, freshwater and marine systems in South-Western Nigeria

Present study investigated trace element concentrations in either muscles or whole samples of 37 finfish and crustaceans harvested with gillnet from fresh (Olomore), marine (Eti osa) and brackish (Lekki Lagoon) waters of Ogun and Lagos states, Nigeria between June and August 2013. Trace elements were determined using ICP-MS after digestion with a microwave autoclave system. The results revealed that the general trend of trace elements in the sampled finfish and crustaceans was marine > brackish > freshwater. If all the samples are considered, 16.2% and 13.5% exceeded the 20 μg g−1 and 30 μg g−1 limits for Cu and Zn, respectively, as set by the European Union, while 71%, 50%, 79% of marine, fresh and brackish samples, respectively, exceeded the limit of 48 mg Fe per 60 kg person as set by FAO/WHO. In addition, samples exceeded the acceptable limit set by WHO/FAO, thus adequate efforts should be placed on the monitoring of effluents that are being discharged into open water bodies in Nigeria

Availability and dynamics of organic carbon and nitrogen indices in some soils amended with animal manures and ashes

Abstract Purpose The study evaluated dried manures and manure ashes as alternative products from animal manures, and determined the dynamics of soil nitrogen availability indices and organic carbon release in some soils amended with dried manures and ashes under laboratory incubation, screen-house and field experiments. Methods Cattle, goat and poultry manures were collected and air dried to produce dried manures after which part of the dried manures were burnt in open space at a temperature range of 320–450 °C to produce manure ashes. Treatments which were no amendment (control), dried manures of cattle, goat and poultry manure ashes of cattle, goat and poultry and NPK 15-15-15 at 120 kg N ha−1 were applied to soil. Samples were taken fortnightly after amendment incorporation in the incubation experiment; in screen-house experiment and field experiments, plant seeds were established after amendment incorporation; thereafter, soil samples were taken fortnightly. Soil samples were analyzed for soil organic carbon (SOC), NH4 +–N and NO3 −–N using a spectrophotometer. Results Incineration of manures increased pH, exchangeable cations and carbon, while nitrogen in manures ashes was comparable to nitrogen in dried manures. The application of manure ash increased SOC, NH4 +–N and NO3 −–N by 182, 102, 128% in incubation experiment while 64 and 628% increase in SOC and NH4 +–N was recorded in screen-house experiment, respectively, relative to the control. In the field experiment, a significant increase in NO3 −–N was recorded at the onset of incorporation; nitrification was more pronounced than ammonification under incubation and field conditions. Conclusion Dried manures are not superior to manure ashes and incorporation of manures ashes increased the SOC, NH4 +–N and NO3 −–N though changes with increasing weeks were erratic

Occurrence of selected polybrominated diphenyl ethers and 2,2′,4,4′,5,5′ hexabromobiphenyl (bb-153) in sewage sludge and effluent samples of a wastewater-treatment plant in Cape Town, South Africa.

The reuse of treated effluent from wastewater treatment plants (WWTPs) as alternative water source for sport-field or landscape irrigation, agricultural, and other industrial purposes is growing significantly. Similarly, the application of treated sludge (biosolid) to agricultural soils is now being considered globally as the most economic means of sludge disposal. However, the presence of emerging organic contaminants in these matrices, including polybrominated diphenyl ethers (PBDEs), which are potential endocrine disruptors, portends a high health risk to humans and the environment in general. In this study, effluent and sewage sludge samples collected from a WWTP were analysed for some selected PBDE congeners (BDE congeners 28, 47, 99 100 153 154 183, and 209) as well as BB-153 using a high-capillary gas chromatograph equipped with an electron capture detector. The sum of the eight PBDE congeners ranged from 369 to 4370, 19.2 to 2640, and 90.4 to 15,100 ng/l for raw water, secondary effluent, and final effluent, respectively. A similar result was observed for sewage sludge samples, which ranged between 13.1 and 652 ng/g dry weight (dw). The results obtained for BB-153 were generally lower compared with those found for most PBDE congeners. These ranged from ND to 18.4 ng/l and ND to 9.97 ng/g dw for effluents and sewage sludge, respectively. In both matrices, BDE 47 and 209 congeners were found to contribute significantly to the overall sum of PBDEs. The reuse of the treated effluent, particularly for agricultural purposes, could enhance the possibility of these contaminants entering into the food chain, thus causing undesirable health problems in exposed subjects

Heavy Metals Speciation and Human Health Risk Assessment at an Illegal Gold Mining Site in Igun, Osun State, Nigeria

Background. There is increasing global concern over the health effects of heavy metals arising from various anthropogenic activities, especially mining. Mining activities in developing countries are often carried out at an artisanal level using a variety of extraction methods with human health and environmental consequences. Objectives. The broad objective of this study is to assess the chemical forms, distribution pattern, and health risks due to mining and processing techniques at a gold mining site in Igun, Osun State, Nigeria. Methods. Samples were collected from 28 active mine pits and sequentially extracted using standard methods. Extracts were analyzed for metals using inductively coupled plasma optical emission spectrometer (ICP/OES), while health risk was assessed using United States Environmental Protection Agency (USEPA) and Dutch methods. Chemical speciation of heavy metals and health risk assessment was calculated using mobile phase fraction summation. Results. Metals were exclusively present in the residual fractions, indicating that these metals are strongly bound to the resistant components of the soil matrix. The percentage in the residual fraction ranged from 9.41% (tin) to 99.42% (aluminium). The heavy metals geoaccumulation index for the site ranged from 0 (no contamination) to 6 (extremely contaminated). The cancer risk ranged from 6.17E-13 to 7.77E-05 and 2.73E-12 to 4.64E-04 for adults and children, respectively. Discussion. Cancer risk and non-cancer risk (hazard index) assessment showed that arsenic poses a higher risk in adults and children compared to other metals through the dermal exposure route. Competing Interests. The authors declare no competing financial interests

Phyto-metals screening of selected anti-diabetic herbs and infused concoctions

Objective: To determine the levels of some selected heavy metals in both the selected anti-diabetic herbal plants and infused concoctions for diabetes treatment. Methods: Ten anti-diabetic plant samples: pawpaw leaves (Carica papaya), bitter melon leaves (Momordica charantia), holy basil leaves (Ocimum sanctum), bitter leaf (Vernonia amygdalina), ginger rhizome (Zingiber officinale), garlic (Allium sativum), African red pepper fruits (Capsicum frutescens), negro pepper grain (Xylopia aethiopica), cashew leaves (Anacardium occidentale) and onion bulb (Allium cepa) were evaluated for heavy metals. These were digested using standard methods and analyzed for manganese, copper, nickel, chromium, zinc, cadmium and lead using atomic absorption spectrophotometer. The infused concoctions (I and II) prepared from these medicinal herbs administered to diabetic patients were also analyzed for these heavy metals. Concoction I contained all the plants and honey with the exception of Momordica charantia and Ocimum sanctum which constituted concoction II with water only. The data obtained were subject to descriptive (mean and standard deviation) and inferential (ANOVA and DMRT) statistics. Results: Chromium and nickel levels were below detection limits in concoction I while manganese [(0.11 ± 0.01) μg/g] and zinc [(0.09 ± 0.01) μg/g] were detected in concoction II. Honey contained manganese [(0.10 ± 0.01) μg/g] and nickel [(0.70 ± 0.01) μg/g]. The anti-diabetic medicinal herbs and infused concoctions (I and II) were observed to contain heavy metals below the compared limits. Conclusions: The study thus shows that the herbs and concoctions are safe from the heavy metals considered. However, right dosage of the anti-diabetic concoctions should always be considered to prevent possible chronic side effects from bio-accumulation of heavy metals