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)

Antimicrobial resistance screening and profiles: A glimpse from the South African perspective

According to the Centre for Disease Dynamics Economics and Policy, South Africa represents a paradox of antibiotic management similar to other developing countries, with both overuse and underuse (resulting from lack of access) of antibiotics. In addition, wastewater reuse may contribute towards antibiotic resistance through selective pressure that increases resistance in native bacteria and on clinically relevant bacteria, increasing resistance profiles of the common pathogens. Sediments of surface water bodies and wastewater sludge provide a place where antibiotic resistance genes are transferred to other bacteria. Crop irrigation is thought to be a potential source of exposure to antibiotic-resistant bacteria through the transfer from the water or sludge into crops. The objectives of this study were to examine the antibiotic-resistance profiles of Escherishia coli from three agricultural locations in the Western Cape, South Africa. Using a classical microbiology culture approach, the resistance profiles of E. coli species isolated from river water and sediments, farm dams and their sediments and a passive algal wastewater treatment ponds and sediment used for crop irrigation were assessed for resistance to 13 commonly used antibiotics. Randomly selected E. coli isolates from the sediment and water were tested for resistance

Endocrine disrupting chemicals in commercially available cling film brands in South Africa

Cling films comprise of plasticizers which are known endocrine disrupting chemicals (EDCs). Cling films are commonly used for food packaging and EDCs may leach into food, increasing exposure, leading to adverse health outcomes. We determined the levels of common selected EDCs expected in commercial cling film brands sold in South Africa. We tested for para-nonylphenol (p-NP), bisphenol A (BPA), bis(2-ethylhexyl) adipate (DEHA), and phthalates [di-2-ethyhexyl phthalate (DEHP) and dibutylphthalate (DBP)]. We selected eight brands of cling film and used standard chromatography methods to extract compounds. We found p-NP in one brand (2.06 µg/kg) and BPA in two brands (1.48 and 1.61 µg/kg). Five brands contained DEHP (2.1–2.59 mg/kg), DBP (0.62–1.21 mg/kg) and DEHA (165.89–674.07 mg/kg). Levels of DEHA and DEHP in the cling film are associated with potential human health risks. The maximum level of DEHA ranged from 1.6 to 16 times the safe level, with a calculated hazard quotient of 1.4. The two cling film brands made from low density polyethylene (LDPE), both endorsed by the Cancer Association of South Africa (CANSA), had target chemicals below the detection limit.http://www.tandfonline.com/loi/bher202020-05-23hj2019School of Health Systems and Public Health (SHSPH)Urolog

Health risk implications from simultaneous exposure to multiple environmental contaminants

Water quality has deteriorated in the upper Olifants River system, South Africa, as a result of land use activities which include mining, agriculture and industries. A health risk assessment was conducted from 2009 to 2011 in the catchment to determine the possible risks local communities face from various pollutants such as microbials, heavy metals and oestrogen in the river water and vegetation. Aluminium and manganese accumulated in plants and vanadium and aluminium concentrations found in selective water samples posed significant health risks when consumed. A quantitative microbial risk assessment revealed that the combined risk of infection ranged from 1 to 26 percent with the Norovirus posing the overall greatest health risk. The anticipated disability adjusted life years resulting from drinking untreated water from these sites are in the order of 10,000 times greater than what is considered acceptable. The oestradiol activity, caused by endocrine disrupting compounds in the water, measured above the trigger value of 0.7 ng L−1. Impoverished communities in the area, who partially depend on river water for potable and domestic use, are exposed to immune-compromising metals that increase their probability of infection from waterborne diseases caused by the excess microbial pathogens in the contaminated surface water.Olifants River Forumhttp://www.elsevier.com/locate/ecoenvhb201

Estrogenic activity, chemical levels and health risk assessment of municipal distribution point water from Pretoria and Cape Town, South Africa

Endocrine disrupting chemicals (EDCs) are ubiquitous in the environment and have been detected in drinking water from various countries. Although various water treatment processes can remove EDCs, chemicals can also migrate from pipes that transport water and contaminate drinking water. This study investigated the estrogenic activity in drinking water from various distribution points in Pretoria (City of Tshwane) (n = 40) and Cape Town (n = 40), South Africa, using the recombinant yeast estrogen screen (YES) and the T47D-KBluc reporter gene assay. The samples were collected seasonally over four sampling periods. The samples were also analysed for bisphenol A (BPA), nonylphenol (NP), di(2-ethylhexyl) adipate (DEHA), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisononylphthalate (DINP), 17β-estradiol (E2), estrone (E1) and ethynylestradiol (EE2) using ultra-performance liquid chromatography-tandem mass spectrophotometry (UPLC-MS/MS). This was followed by a scenario based health risk assessment to assess the carcinogenic and toxic human health risks associated with the consumption of distribution point water. None of the water extracts from the distribution points were above the detection limit in the YES bioassay, but the EEq values ranged from 0.002 to 0.114 ng/L using the T47D-KBluc bioassay. BPA, DEHA, DBP, DEHP, DINP E1, E2, and EE2 were detected in distribution point water samples. NP was below the detection limit for all the samples. The estrogenic activity and levels of target chemicals were comparable to the levels found in other countries. Overall the health risk assessment revealed acceptable health and carcinogenic risks associated with the consumption of distribution point water.The South African Medical Research Councilhttp://www.elsevier.com/locate/chemosphere2018-11-30hj2017School of Health Systems and Public Health (SHSPH)Urolog

Strengthening the knowledge base to face the impacts of climate change on water resources in Africa : a social innovation perspective

Abstract: While it is increasingly important to strengthen the existing knowledge base in Africa to adequately respond to the rising risks and impacts of climate change on water resources, a significant research gap remains to identify areas and mechanisms to cope with these societal challenges. The aim of the paper is twofold: i) to provide subject-specific insights by analyzing the current knowledge base in Africa given water-related challenges due to climate change, and ii) to offer methodological insights into how a knowledge base can be studied comprehensively. This study overcomes the limitations of existing studies by combining two different perspectives, namely a thematic focus on six societal challenges and a conceptual focus on five social innovation dimensions. It does so by undertaking an innovative qualitative analysis that combines both top-down and bottom-up perspectives. Top-down, it explores the extent to which five social innovation dimensions are included and addressed in policy agendas and action plans. Bottom-up, it explores the perception of African experts and practitioners in how these knowledge gaps should be addressed. The research identifies a strong bias in the policy arena towards water security versus other water-related societal challenges. Our research suggests that rather than focusing on traditional policy instruments, water-related societal challenges should be addressed by joint attention to all five social innovation dimensions. There is a strong call from practitioners and experts towards strengthening the existing knowledge base by engaging local realities and local stakeholders and for the involvement of business and private sector actors

Environmental Risk Characterization of an Antiretroviral (ARV) Lamivudine in Ecosystems

Antiretroviral drugs for the treatment of human immunodeficiency virus (HIV) and other viral infections are among the emerging contaminants considered for ecological risk assessment. These compounds have been reported to be widely distributed in water bodies and other aquatic environments, while data concerning the risk they may pose to unintended non-target species in a different ecosystem (environment) is scanty. In South Africa and other developing countries, lamivudine is one of the common antiretrovirals applied. Despite this, little is known about its environmental impacts as an emerging contaminant. The present study employed a battery of ecotoxicity bioassays to assess the environmental threat lamivudine poses to aquatic fauna and flora. Daphnia magna (filter feeders), the Ames bacterial mutagenicity test, Lactuca sativa (lettuce) germination test, and the Allium cepa root tip assay were conducted, testing lamivudine at two concentrations (10 and 100 µg/L), with environmental relevance. The Daphnia magna toxicity test revealed a statistically significant response (p << 0.05) with a mortality rate of 85% on exposure to 100 µg/L lamivudine in freshwater, which increased to 100% at 48-h exposure. At lower concentrations of 10 µg/L lamivudine, 90% and 55% survival rates were observed at 24 h and 48 h, respectively. No potential mutagenic effects were observed from the Ames test at both concentrations of lamivudine. Allium cepa bioassays revealed a noticeable adverse impact on the root lengths on exposure to 100 µg/L lamivudine. This impact was further investigated through microscopic examination, revealing some chromosomal aberration in the exposed Allium cepa root tips. The Lactuca sativa bioassay showed a slight adverse impact on both the germination rate of the seeds and their respective hypocotyl lengths compared to the control. Overall, this indicates that lamivudine poses an ecological health risk at different trophic levels, to both flora and fauna, at concentrations previously found in the environment

Multi-residue method for the determination of selected veterinary pharmaceutical residues in surface water around Livestock Agricultural farms

A multi-residue method for the determination of the occurrence and prevalence levels of selected veterinary pharmaceutical residues in surface water was developed on a high performance liquid chromatography coupled to ultraviolet-visible (HPLC-UV) detector, and tested with the intent of profiling their distribution. The limit of detection (LOD) and limit of quantitation (LOQ) achieved for the selected pharmaceuticals; acetaminophen, diclofenac, salicylic acid, tetracycline, chloramphenicol, ciprofloxacin, bisphenol–A, 17β–estradiol, estriol, and ivermectin ranged between 0.06–3.45 μg L−1 and 0.17–10.35 μg L−1 respectively. Other International Conference on Harmonization (ICH) parameters for validation of analytical procedures were also evaluated and discussed. Pharmaceutical residues were recovered from surface water samples collected from around livestock farms in Cape Town, South Africa by solid phase extraction (SPE), and thereafter separated and quantified using a validated method on a HPLC-UV-detector. Most frequently detected residues were: acetaminophen (56%), diclofenac (53), tetracycline (72%), 17β–estradiol (73%); chloramphenicol (68%), and salicylic acid (67%), with significantly high (p > 0.05) spatial variability in the concentration distributions of the pharmaceuticals in the surface waters