Global Pollution

Genetic characterization of the airborne resistomes (multidrug resistant organisms) in the outdoor environment of Bangladesh with their temporospatial diversity and clinical significance

Author: Muhammad Asaduzzaman1
Author Affiliation: 1International Centre for Diarrheal Disease Research, Bangladesh

Antibiotic resistance (AMR) has been widely recognised as a global threat to human health which costs for significant annual deaths worldwide. Along with use in human therapy, antibiotics are used in an extensive way in animal farming specially food animal and agricultural field and eventually, a large amount of antibiotic and their residues are disseminated in the environment both air and water. So, the environment is recognised as an important reservoir of antibiotic resistant bacteria, enhancing the horizontal transfer of resistant genes. But, there is no comprehensive information of airborne resistant organism (resistomes) in Bangladesh that carry genes conferring resistance to antibiotics. Even, the capacity to carry and propagate resistance of these resistomes is poorly studied worldwide. Again, the environmental risks of AMR transmission are likely to change dramatically with seasonal and rainfall variability. So, the quantity of organisms and diversity of antimicrobial resistance genes (ARGs) will vary in air of different environments in different seasons. This study addresses not only the presence and characterization of resistant organisms in air using different phenotypic and genotypic methods but also the clonal distribution of those organisms with seasonal variation. Therefore, the risky environments can be identified effectively including humans and animals.

This cross sectional study is being conducted at four distinct outdoor environments – i)urban live poultry markets and ii) commercial poultry farms in peri-urban sites iii) peri-urban households and iv) Urban residential area in Dhaka metropolitan area and Mirzapur Upazilla of Tangail district for which Environmental systematic and grid sampling are used. To identify the temporal diversity, air samples are collected in both wet (August- October’2017) and dry (January-March’18) seasons by active microbial air sampler through multiple culture media to obtain both gram positive and gram negative resistant organisms.

The study is ongoing and the results will be presented at the annual meeting. A large number of 3rd generation cephalosporin (3GC) and Carbapenem as well as Oxacillin and Vancomycin resistant organisms have been found which will be further analysed by qPCR and metagenomics.

Geospatial mapping of the concentrations of AMR bacteria in environmental compartments will help to identify the hotspots of resistant bacteria and their clonal relationship will be used to inform scientific community a new planetary health insight regarding the spread of antibiotic resistance to human.

Public health and solid waste management in Sub-Saharan African cities: a study of Johannesburg, South Africa

Author: Nzalalemba Serge Kubanza1
Author Affiliation: 1School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand

This paper discusses the impacts of solid waste on human health and environmental wellbeing in Johannesburg, South Africa. Using both secondary and primary data collected through semi-structured interviews with members of a local community of Windsor, municipal officials and other stakeholders involved in solid waste management in Johannesburg, it finds that mismanagement of solid waste negatively affects the urban environment and human health, leading to reduced productivity and economic growth. Further, it is argued that ineffective solid waste management must be seen as a consequence both of institutionalized failure to implement and enforce urban policies and regulations and a parallel failure to recognize the importance of private agents and community participation in urban development and management. Developing an effective and sustainable solid waste management system in Johannesburg requires city authorities to devolve resources and authority to local along with clear guidelines and strategies to strengthen local management processes.

Unintended consequences of pharmaceutical pollutants: insights from population-level surveys and point-of-care interviews to identify points of intervention

Author: Christine Vatovec1,2,3
Author Affiliation: 1Gund Institute for Environment; 2Larner College of Medicine; 3Rubenstein School of Environment and Natural Resources, University of Vermont

BACKGROUND: Pharmaceuticals are classified as chemicals of emerging concern because of the unintended consequences they pose to the health of aquatic ecosystems. The biological activity that makes many medications valuable to human health can persist in natural environments after human excretion and disposal. These persistent chemicals can lead to behavioral and physiological changes in several aquatic species. After observing the disposal of unused medications down-the-drain in a variety of healthcare settings, we sampled wastewater entering Lake Champlain in Vermont, USA, and detected 51 pharmaceuticals directly entering the lake via effluent. The aims of the on-going studies reported here are 1) to examine the social governance of pharmaceutical pollution, and 2) identify key points of intervention to minimize the effects of these chemicals on aquatic environments.

METHODS: This research employs mixed social science methods including surveys to examine consumer purchasing, use, and disposal behaviors as sources of pharmaceutical pollution, and interviews to provide insight on clinical prescribing and dispensing practices.

FINDINGS: We share results from four interrelated studies that each provide insight on pharmaceutical pollutants resulting from different populations and various social governance factors. 1) A survey of university students (n = 358) indicates that leftover drugs pose disposal concerns among this young adult population, and that this demographic is unaware of appropriate disposal options for unwanted medications. 2) A survey of Burlington, Vermont residents (n = 161) indicates that flushing is not a major source of pharmaceutical pollution in wastewater effluent. 3) A survey of Vermont residents (n = 421) indicates that both human and veterinary medications are sources of pollution. 4) Interviews with clinicians and pharmacists suggest that the political economy of pharmaceutical prescribing and dispensing is a key point of intervention for minimizing pollution.

INTERPRETATION: The social governance of pharmaceutical contaminants in the aquatic environment is a complex system that involves both a lack of awareness at the consumer level and complex, contradicting directives at the institutional level. The surveys reported here indicate that large volumes of both prescription and over-the-counter drugs go unused and require appropriate disposal (currently high-heat incineration at a licensed facility), but that access to and awareness of disposal options is limited across all populations surveyed. Interviews with healthcare providers indicate several prescribing and dispensing practices that lead to leftover medications that require disposal. Key points of intervention include promoting appropriate disposal through existing policies, and decreasing the volume of drugs prescribed and dispensed.

Digestion of aquaculture effluent and Saccharina latissima as a sustainable form of nutrient recycling in aquaponics/ hydroponics

Authors: Dylan Turner1, Jeri Fox1, Zach Miller-Hope1
Author Affiliations: 1University of New England

Traditional aquaculture has been seen as environmentally neutral due to its use of waste products as inputs of nutrients and food. Relatively recently as modern aquaculture took off, commercial feeds have been made available and have led to cause for environmental concern. The rise of modern aquaculture has increased nutrient emissions from aquaculture facilities due to a lack of efficiency in feeds and filtration. Recirculating aquaculture systems (RAS) have also grown in popularity in recent years largely to help mitigate water pollution caused by flow through systems. There is a need for these systems to help control nutrient pollution and be more efficient with their inputs. Maine is quickly becoming a hub for aquaculture ventures, meaning more solid waste from fish but also other waste resources such as seaweed. Seaweed harvest is increasing annually with little outlet (No processing and not a large consumer base) and it is also a nutrient rich resource. This research proposes a method to recycle both aquaculture waste and seaweed to create a nutrient rich fertilizer that could be used in aquaponics, hydroponics, or traditional agriculture.

Digestions (Hydrolysis and fermentation) are going to be performed on both sludge from an aquaculture system as well as Saccharina latissima to break down both components and mobilize the nutrients. These digestions will be carried out under both aerobic and anaerobic conditions to determine if there is a difference in nutrient mobilization under different conditions. Nutrient analysis will be done to determine overall concentrations of nutrients and how much is brought into a usable form for plants.

Preliminary results show a combination of anaerobic and aerobic digestion mobilizes important macro and micronutrients such as phosphorus, potassium, iron, sulfur, and potentially more.

These preliminary findings suggest that there is a useful alternative for aquaculture waste as well as an outlet for the Maine seaweed industry which has some wide-reaching implications. If implemented this would bring many aquaculture practices closer to a fully sustainable system, reducing the amount of nutrient pollution in many coastal areas. It would create an animal based fertilizer to be used in aquaponics and hydroponics, making it easier to be certified organic, and make both more feasible options for growing food. Lastly, it would create an alternative revenue stream for aquaculture businesses that promotes sustainability.

Aflatoxin Contamination of Village Grains in Central Tanzania: Food and Agricultural Practices in Relation to Contamination and Exposure Risk

Authors: Godfrey Magoke1,2Robyn Alders2, Mark Krockenberger3, Wayne L. Bryden4, Furaha Mramba1, Wende Maulaga1
Author Affiliations: 1Tanzania Veterinary Laboratory Agency, Temeke Veterinari, Dar es Salaam2School of Life and Environmental Science, University of Sydney; 3Sydney School of Veterinary Science, University of Sydney; 4School of Agriculture and Food Sciences, University of Queensland

A study was conducted in the semi-arid Manyoni District of Central Tanzania, involving eight village communities to: 1) determine the degree of aflatoxin contamination of village grains immediately postharvest and following storage; and 2) gain knowledge of grain food production practices and food habits so as to identify areas where interventions to mitigate potential aflatoxin contamination are best employed.

Grain samples were randomly selected immediately post-harvest (n=134) and following 6 months or more after storage (n=157). Sample screening (AflaCheckTM, Vicam) was followed by quantitative determination of samples containing ≥10 µg/kg total aflatoxins by the HPLC. To understand community knowledge, responses were sought from 76 randomly selected adults (55 women, 21 men) by a questionnaire covering pre-harvest, harvest and post-harvest practices, food preparation and knowledge on food toxins.

The grain categories and proportion of positive samples (≥10 µg/kg) for immediate post-harvest and storage grains respectively, were; maize (8/35, 22/47), groundnut (8/39, 4/17), sorghum (2/24, 5/41), rice (0/6, 1/8), bulrush millet (0/6, 0/7), sesame (2/11, 2/23), sunflower seeds (0/9, 2/10), and green gram (2/4, 3/4). Contamination was more significant in maize and groundnut and ranged up to 192 µg/kg and 198 µg/kg respectively in immediate post-harvest samples and 213 µg/kg and 351 µg/kg respectively in storage samples. Respondent questionnaires revealed farmers: had no knowledge of food toxins; received limited extension services; did not generally use irrigation, fertilizers or pesticides; relied on inefficient harvesting, drying and storage technologies; and frequently consumed unpolished grains.

Village grains in Central Tanzania may contain high concentrations of aflatoxins. Existing practices and lack of food toxin knowledge may contribute to contamination and exposure. Therefore, farmers would benefit from better extension services, using livestock manure as fertilizer, being assisted with drought tolerant seeds, better harvesting, drying and storage technologies to achieve safe food production, resulting in improved maternal and child nutrition.

Extreme precipitation events and water quality in California: Implications for human health in a varying and changing climate

Authors: Alexander Gershunov1Tarik Benmarhnia1,2, Rosana Aguilera1
Author Affiliations: 1Scripps Institution of Oceanography, University of California San Diego; 2Department of Family Medicine and Public Health, University of California San Diego;

Most pathogens and pollutants collect on the land surface or in infrastructure between strong rainfall episodes, and are then mobilized and delivered via storm runoff to areas of human exposure, such as coastal recreational waters, as a consequence of sewage or water treatment systems overflow. In California, USA, precipitation events are projected to become more extreme, and at the same time decrease in frequency as storm tracks move poleward due to polar-amplified global warming. Precipitation extremes in California are dominated by atmospheric rivers (ARs), which carry more moisture in a warmer climate. Thus, the physical driver of extreme precipitation events in this region is expected to grow stronger with climate change, and pollutant accumulation and runoff-generated exposure to those pollutants are expected to increase, particularly after prolonged dry spells. Extreme precipitation effects on water quality and associated human health impacts have been related to waterborne disease outbreaks in the conterminous USA and associated with beach closings in coastal areas due to the flushing of fecal contaminants through storm drains. In southern California, microbiological contamination of water during winter storms exposes human populations to elevated concentrations of microorganisms in bathing waters at beaches, which could cause gastrointestinal and ear infections, and lead to exposure to pathogens causing life-threatening conditions, e.g. hepatitis A. For this purpose, we use a recently published catalog of ARs, in combination with historical daily precipitation and fecal pollution indicators such as total and fecal coliforms in coastal waters to explore associations between extreme events related to ARs and the variability in coastal water quality in California. These associations will be used to identify mechanisms of fecal pollutant delivery to coastal recreational waters via storm runoff and to track sources of pollution common in the region, such as sewage outfalls and homeless encampments near rivers and streams. Overall, this work aims to quantitatively assess the influence of precipitation regime changes on human health via exposure to recreational coastal waters in California, with the ultimate goal of reducing vulnerability to extreme weather, as well as to delineate measures, such as an early warning system, that improve the response and resilience of human populations and ecosystems to a varying and changing climate.

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