Spatial and temporal trends of polychlorinated biphenyls in water and sediment from Nairobi River, Kenya

Ndunda, Elizabeth N.; Wandiga, Shem O.

doi:10.1007/s10661-020-08566-x

Cited by 9 publications

(4 citation statements)

References 25 publications

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“…S4b ), the overall trend of the total concentration of the organic pollutants was: downstream (the average value was 1369.42 ng L −1 ) > midstream (1252.69 ng L −1 ) > upstream (1142.19 ng L −1 ). This spatial variation can be attributed to pollutants generated by human activities along the river, which flow downstream with the river's current, thereby contributing to increased concentrations in downstream areas [ 47 ]. Notably, the highest annual average concentration was recorded in the downstream section of Suzhou (S22), reaching 1684.62 ng L −1 .…”

Section: Resultsmentioning

confidence: 99%

Evaluating a river's ecological health: A multidimensional approach

Zhao,

Zhang,

et al. 2024

Environmental Science and Ecotechnology

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Section: Resultsmentioning

confidence: 99%

Evaluating a river's ecological health: A multidimensional approach

Zhao,

Zhang,

et al. 2024

Environmental Science and Ecotechnology

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“…They include microplastics, pharmaceuticals, hormones, personal care products, pesticides, and other persistent organic pollutants (Bayabil et al, 2022; Fang, 2021; Gani et al, 2021; Lambert & Wagner, 2018; Shehu et al, 2022). Alarming concentrations of CECs have been detected in various water sources in Kenya (Abbasi & Mannaerts, 2018; Ndunda & Wandiga, 2020; Otieno et al, 2013), but the number of such studies remains relatively low in Kenya. In addition, there are no legal maximum allowable limits for some of these compounds in different environmental matrices because the available data remain largely insufficient for an ideal comprehensive report and for decision‐making (Brachner et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Decadal Assessment of Microplastics, Pharmaceuticals, and Pesticides as Contaminants of Emerging Concern in Kenya's Surface Waters: A Review

Githaiga

Njuguna

Bargul

et al. 2023

Enviro Toxic and Chemistry

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Studies investigating microplastics, pharmaceuticals, and pesticides as contaminants of emerging concern (CECs) in surface water sources in Kenya are reviewed. Contaminants of emerging concern are chemicals that have recently been discovered that may pose a threat to the environment, aquatic life, and human life. Microplastics in surface waters range from 1.56 to as high as 4520 particles/m3, with high concentrations recorded in coastal waters. The dominant microplastics are fibers, fragments, and films, with foams, granules, and pellets making up only a small percentage. The main source of pharmaceuticals in water sources is not wastewater‐treatment plants but rather raw untreated sewage because high concentrations are found near informal settlements with poor sewage connectivity. Antibiotics are detected in the range of the limit of quantification to 320 μg/L, with sulfamethoxazole, trimethoprim, and ciprofloxacin being the most abundant antibiotics. The high frequency of detection is attributed to the general misuse of antibiotics in the country. A health risk assessment indicated that only ciprofloxacin and acetaminophen posed noncarcinogenic health risks in the Ndarugo River and Mombasa periurban creeks, respectively. Similarly, the detection of antiretroviral drugs, mainly lamivudine, nevirapine, and zidovudine, is associated with human immunodeficiency virus prevalence in Kenya. In the Lake Naivasha, Nairobi River, and Lake Victoria basins, frequently detected organochloride pesticides (OCPs) are methoxychlor, alachlor, endrin, dieldrin, endosulfan, endosulfan sulfate, α‐hexachlorocyclohexane (α‐HCH), γ‐HCH, and dichlorodiphenyltrichloroethane (DDT), some of which occur above permissible concentrations. The presence of DDT in some sites translates to illegal use or historical application. The majority of individual OCPs posed no noncarcinogenic health risk, except dieldrin and aldrin which had a hazard quotient >1 in two sites. Therefore, more surveying and regular monitoring in different regions in Kenya concerning CECs is essential to determine the spatial variability and effective measures to be taken to reduce pollution. Environ Toxicol Chem 2023;00:1–14. © 2023 SETAC.

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“…Once in the environment, PCBs are transported over long distances owing to their long range transport property where they bind strongly to soil and sediment that act as secondary sources of PCBs through volatilizations 7 . Polychlorinated biphenyls have been reported in various environmental media ranging from indoor air 8 , 9 , water and sediment 10 , 11 and soil 12 . Of great concern is that these chemicals enter into the food chain where human beings are exposed mainly through the diet and breathing contaminated air, having been detected in human tissue including blood 13 , adipose tissue 14 , liver and kidney 15 .…”

Section: Introductionmentioning

confidence: 99%

“…Routine reporting on contamination of the environment with PCBs serves as a way of tracking pollution sources with a view to eliminate them 18 . Their separation and detection in the environmental samples has been achieved by use of chromatographic techniques with electron capture detector (GC-ECD) or mass spectrometer as the detection systems 10 , 19 , 20 and recently the sensitive and selective high and low resolution mass-spectrometry (HR/LS-MS) 21 , 22 . These techniques are highly sensitive and have been able to provide the required information albeit with high cost implications that do not favor routine monitoring.…”

Section: Introductionmentioning

confidence: 99%

Towards miniaturized electrochemical sensors for monitoring of polychlorinated biphenyls

Ndunda¹,

Mwanza²

2023

Open Res Africa

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Pollution of our environment as a result of industrialization and other human activities is a growing concern due to the harmful effects of most chemicals that are released into the environment. Of particular interest are the persistent organic pollutants (POPs) that are reported to be toxic and build up in the environment due to their persistence. Among the POPs are polychlorinated biphenyls (PCBs), which were widely used in the past in various applications ranging from additives in pesticides to dielectric fluids in electrical equipment. As a way of protecting the one health trilogy (environment, human and animal health), their determination in the environment is a paramount call that has seen researchers continue to provide advanced technologies towards achieving this goal. These technologies involve the conventional gold standard gas chromatography systems coupled to sensitive detectors that can detect trace level concentrations. They have come in handy in monitoring of PCBs but their application for routing monitoring may not be sustainable because of the cost of operation associated with them and the need for experts to run the equipment. As a result, there is need for affordable systems that are still able to achieve the required sensitivity for routine monitoring and real-time data acquisition. Sensor systems fit very well in this category since they can be miniaturized for affordability and portray many other desirable features. PCBs as environmentally relevant environmental pollutants have received minimal attention with regards to sensor development and this review highlights the efforts that have been made so far. It provides in-depth discussions on electrochemical sensors and the various modifications that have been employed to date to achieve detection of PCBs at low concentrations as well as the future prospects in remote and routine monitoring.

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Spatial and temporal trends of polychlorinated biphenyls in water and sediment from Nairobi River, Kenya

Cited by 9 publications

References 25 publications

Evaluating a river's ecological health: A multidimensional approach

Evaluating a river's ecological health: A multidimensional approach

Decadal Assessment of Microplastics, Pharmaceuticals, and Pesticides as Contaminants of Emerging Concern in Kenya's Surface Waters: A Review

Towards miniaturized electrochemical sensors for monitoring of polychlorinated biphenyls

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