Pharmaceuticals and personal care products and heavy metals in the Ganga River, India: Distribution, ecological and human health risk assessment.

In the present study, pharmaceuticals and personal care products (PPCPs), endocrine disrupting compounds (EDCs), and heavy metals (HMs), were measured in water and sediment of the Ganga River during summer and winter seasons for two consecutive years. Additionally, this study estimated the ecological and human health risks associated with PPCPs, EDCs, and HMs. HMs detected in the range of not detected (n.d.) to 23.59 µg/L and 0.01-391.44 µg/g in water and sediment samples, respectively. All studied HMs were within the permissible limits, except for As in water, and Cr and Ni in sediment. The geo-accumulation index (Igeo) indicated that Cr (0.71-5.98) and Pb (0.90-3.90) had high Igeo compared to other metals in sediment samples. Pb showed the highest ecological risk, followed by Cd, Co, Ni, Cu, Cr, As, and Zn. The maximum potential ecological risk index was observed at site G8. The hazard index (HI) value for water (0.08-0.89) and sediment (0.02-0.29) intake by adults remained within the acceptable limits, except at sites G8 (1.27) and G9 (1.34) for water intake. However, for children, the HI value was above the acceptable limit for water intake at sites G4 to G13 and for sediment at site G8. Among the studied compounds, metformin, triclosan, triclocarban, diclofenac, and methylparaben were the most abundant compounds present in the Ganga River. PPCPs and EDCs detected in the range of n.d. to 5850.04 ng/L and n.d. to 1080.41 ng/g in water and sediment samples, respectively. The environmental risk assessment identifies the maximum ecological risk in water exhibited by triclocarban followed by 17α-ethinylestradiol (EE2), diclofenac, and triclosan, while in sediment, the maximum ecological risk exhibited by triclocarban, followed by EE2, 17 ß-estradiol (E2), triclosan, and diclofenac. However, none of the compounds showed human health risk, except for EE2, E2, and atenolol.

Risk management for second-hand clothing imports in least developed countries: Legislations and perception of public-sector corruption.

The second-hand clothing imports are very popular in the least developed countries (LDCs). The social health risk (SHR) associated with second-hand clothing products and the lack of relevant legislations in LDCs, however, bring substantial challenges. This article is therefore developed to explore the sterilization legislation design for second-hand clothing supply chains in LDCs. To address LDCs' different import requirements of fumigation, both the extended exporter responsibility (EER) legislation scheme and the extended importer responsibility (EIR) legislation scheme are considered. We also examine whether the perception of public-sector corruption in LDCs may affect the performance of sterilization legislation schemes. We compare the performance of sterilization legislation schemes under different public-sector corruption cases, different sterilization legislation structures, as well as market competition. Interestingly, our analyses show that the EER and EIR legislation schemes can achieve the same performance under a per unit SHR duty, no matter whether there is public-sector corruption or not. However, these two legislation schemes perform differently under the lump-sum SHR duty. Besides, with the presence of the public-sector corruption perception, the prospect of financial benefits from bribing the regulatory agency can induce the firm to choose a higher optimal sterilization level when the bribe is sufficiently small. These implications complement the extant knowledge on risk management of second-hand clothing in LDCs, and provide an important guidance regarding the design of sterilization legislations on second-hand clothing imports.

Novel spa type and antimicrobial resistance gene profiles of Staphylococcus aureus strains isolated from bovine mastitis in Jordan.

Staphylococcu aureus is the most prevalent microorganism associated with mastitis in cattle. This study was designed to determine the spa types of Staph. aureus and to assess the resistance genes profile of isolated strains in dairy farms in Jordan. In total, 747 milk samples of cattle suffering from subclinical mastitis were collected from 37 dairy farms and tested for Staph. aureus. To detect antimicrobial resistance genes, all 219 strains of Staph. aureus were tested. Furthermore, 21 isolates of Staph. aureus were typed using spa typing. As a result, different proportions of resistance genes were found for Staph. aureus. High resistance genes were in tetK 100%, blaZ 99%, and tetM 97%. Moderate resistance genes were in aac(6')/aph(2'' 52%, ant(4')-Ia 48%, and ermC 41%. Low resistance genes were in ermA is 24%, aph(3')-III is 15%, and mecA is 15%. The spa typing of 21 isolates revealed six spa types, of which five were previously known. For the first time, a novel spa type (t17158) was identified as the main cause of mastitis in dairy cows in Jordan. The identification of resistance genes and spa types is helpful in determining the most effective treatments for cows and plays a significant role in reducing the transmission of pathogens.

Relationship of trihalomethane in drinking water with hypertension and arrhythmia among young and middle-aged adults in Petropavlovsk, Kazakhstan.

There are no studies investigating the association of chlorinated drinking water with the risk of cardiovascular diseases (CVDs) among young and middle-aged adults. This study was aimed to assess the associations between trihalomethanes (THMs) in drinking water and the risk of CVDs in in the target group in Petropavlovsk, Kazakhstan. 448 dwellers of Petropavlovsk were asked about their demographic, socioeconomic, lifestyle, behavioural characteristics, and drinking water preferences. THMs exposure was assessed to each participant based on their residence address. We used multivariable logistic regression analysis to assess the risk of CVDs in young and middle-aged adults. The results showed that the risk of hypertension in the adjusted logistic regression model was increased by 68% and a 2.7-fold in the second and third THM tertiles, respectively. Participants in the second and third THM exposure tertiles had a 2.3-fold and a 4.8-fold increase in the risk of arrhythmia.

Campylobacter spp. prevalence and mitigation strategies in the broiler production chain.

This study aims to discuss the microbial ecology of the broiler gut environment, Campylobacter prevalence across the broiler production chain with a follow-up focus on a possible mitigation strategy, based on the use of bacteriophages. Scientific literature published from the last two decades was reviewed and data were collected to establish the ranges of Campylobacter loads from different samples. Results showed that the pathogen load in the sample is likely to increase from the different stages of the production chain. Contamination of water and feed represents the most notable source of contamination during the primary production, while cross-contamination of broiler carcasses, skin, and meat occurs during the slaughter, dressing, and processing via machinery, work surfaces, water, and air partially due to the leaking of contaminated feces from visceral rupture. Knowledge gaps were identified and included: a lack of studies detecting Campylobacter in broilers in most of the European countries over the last decade and a low number of studies determining the bacterial load in crates used to transport broilers to the slaughterhouse. Determining the prevalence of Campylobacter in the broiler industry will enable us to set critical control points to produce broiler flocks and meat products with a low risk of Campylobacter contamination.

Noise Exposure Assessment at a Secondary School in a City of Pulau Pinang, Malaysia.

Schools are considered sensitive areas to noise pollution. The objective of this study is to ascertain the sound level in schools with respect to different sampling time sessions and sampling points. Five sampling points, consisting of two classrooms (Classroom A and Classroom B), a canteen, a staffroom and a field, were chosen to obtain an overview of the noise level within the whole school in three different time sessions (morning, afternoon and evening), as well as 8-h continuous sampling in both classrooms and the staffroom. The average noise level (LAeq,10min) obtained in this school was found to be in the range of 48.8 dBA to 83.7 dBA, where most of the values exceeded the permissible maximum sound pressure level set by the Malaysian Department of Environment (DOE). Classroom B recorded the highest average noise level (LAeq,8h) of 77.9 dBA, which exceeded the maximum value set by the Department of Environment.

Contested solidarity and vulnerability in social media-based public responses to COVID-19 policies of mobility restrictions in Singapore: a qualitative analysis of temporal evolution.

BACKGROUND: Mobility restriction is the most effective measure to control the spread of infectious disease at its early stage, especially if a cure and vaccine are not available. When control of the coronavirus disease 2019 (COVID-19) required strong precautionary measures, lockdowns were necessarily implemented in countries around the globe. Public health risk communication about the justification and scope of a lockdown was challenging as it involved a conflict between solidarity and individual liberty and a trade-off between various values across groups with different socioeconomic statuses. In the study, we examined public responses to the government-announced "circuit breaker" (a local term for lockdown) at four-time points in Singapore: (1) entry, (2) extension, (3) exit of lockdown 'phase 1' and (4) entry of lockdown 'phase 2'. METHODS: We randomly collected 100 comments from the relevant articles on new organisations' Facebook and Instagram pages and conducted preliminary coding. Later, additional random 20 comments were collected to check the data saturation. Content analysis was focused on identifying themes that emerged from the responses across the four-time points. RESULTS: At the entry, public support for the lockdown was prevalent; yet most responses were abstract with uncertainty. At six weeks of lockdown, initial public responses with uncertainty turned into salient narratives of their lived experiences and hardship with lockdown and unmasking of societal weaknesses caused by COVID-19. At the entry to phase 2, responses were centred on social-economic impact, disparity, and lockdown burnout with the contested notion of continuing solidarity. A temporal pattern was seen in the rationalisation of the lockdown experience from trust, anxiety, attribution of pandemic and lockdown, blaming of non-compliant behaviours, and confusion. CONCLUSIONS: The findings indicated a temporal evolution of public responses from solidarity, attribution of the sustained pandemic, increasing ambiguity towards strong precautionary measures, concerns about economic hardship and mental well-being to worsened social vulnerability, where the government's restrictive policies were questioned with anxiety and confusion. Public health risk communication in response to COVID-19 should be transparent and address health equity and social justice to enhance individual and collective responsibility in protecting the public from the pandemic.

Knowledge, practice, and economic impacts of COVID-19 on small-scale coastal fishing communities in Bangladesh: Policy recommendations for improved livelihoods.

COVID-19 has profoundly impacted global livelihoods and disrupted the food supply chain, including the aquaculture and fisheries industries. Little is known about the response to COVID-19 and the impact it has on incomes, livelihoods and knowledge and practice in the coastal artisanal fishers communities of Bangladesh. Therefore, the aim of this study was to determine the socio-demographics of selected coastal fishers, their knowledge about COVID-19 and the preventive practice taken to reduce it. The impact on their fishing habits and income was also examined to determine potential policy areas. Data were collected via a structured questionnaire from 250 respondents from three coastal districts, Cox's Bazar, Patuakhali and Barguna, Bangladesh during April-June 2020. The research shows that the fishers' knowledge about COVID-19 and measures taken to reduce it were significantly higher in Patuakhali and Barguna than in Cox's Bazar. The pandemic caused lower consumer demand, reduced fish prices and created fish transportation issues due to movement restrictions enforced during the lockdown. Irrespective of geographical location, fishing trips were reduced by frequency and duration compared with the pre-COVID-19 period, consequently lowering the income of fishers. Fishers have received little or no support from private, non-governmental or governmental sources. Considering the evidence in this paper of economic hardship, this paper recommends artisanal fishers in Bangladesh should be provided with support to improve their health education, access to professional health facilities and financial services. This will contribute to improved food security and sustainable livelihoods that can better withstand local and/or global crises.

Optimizing peer review to minimize the risk of retracting COVID-19-related literature.

Retractions of COVID-19 literature in both preprints and the peer-reviewed literature serve as a reminder that there are still challenging issues underlying the integrity of the biomedical literature. The risks to academia become larger when such retractions take place in high-ranking biomedical journals. In some cases, retractions result from unreliable or nonexistent data, an issue that could easily be avoided by having open data policies, but there have also been retractions due to oversight in peer review and editorial verification. As COVID-19 continues to affect academics and societies around the world, failures in peer review might also constitute a public health risk. The effectiveness by which COVID-19 literature is corrected, including through retractions, depends on the stringency of measures in place to detect errors and to correct erroneous literature. It also relies on the stringent implementation of open data policies.

Genetic Compatibility of Reassortants between Avian H5N1 and H9N2 Influenza Viruses with Higher Pathogenicity in Mammals.

The cocirculation of H5N1 and H9N2 avian influenza viruses in birds in Egypt provides reassortment opportunities between these two viruses. However, little is known about the emergence potential of reassortants derived from Egyptian H5N1 and H9N2 viruses and about the biological properties of such reassortants. To evaluate the potential public health risk of reassortants of these viruses, we used reverse genetics to generate the 63 possible reassortants derived from contemporary Egyptian H5N1 and H9N2 viruses, containing the H5N1 surface gene segments and combinations of the H5N1 and H9N2 internal gene segments, and analyzed their genetic compatibility, replication ability, and virulence in mice. Genes in the reassortants showed remarkably high compatibility. The replication of most reassortants was higher than the parental H5N1 virus in human cells. Six reassortants were thought to emerge in birds under neutral or positive selective pressure, and four of them had higher pathogenicity in vivo than the parental H5N1 and H9N2 viruses. Our results indicated that H5N1-H9N2 reassortants could be transmitted efficiently to mammals with significant public health risk if they emerge in Egypt, although the viruses might not emerge frequently in birds.IMPORTANCE Close interaction between avian influenza (AI) viruses and humans in Egypt appears to have resulted in many of the worldwide cases of human infections by both H5N1 and H9N2 AI viruses. Egypt is regarded as a hot spot of AI virus evolution. Although no natural reassortant of H5N1 and H9N2 AI viruses has been reported so far, their cocirculation in Egypt may allow emergence of reassortants that may present a significant public health risk. Using reverse genetics, we report here the first comprehensive data showing that H5N1-N9N2 reassortants have fairly high genetic compatibility and possibly higher pathogenicity in mammals, including humans, than the parental viruses. Our results provide insight into the emergence potential of avian H5N1-H9N2 reassortants that may pose a high public health risk.

Cassava consumption and the occurrence of cyanide in cassava in Vietnam, Indonesia and Philippines.

OBJECTIVE: To make a tentative assessment of the consumption of cassava in three countries in South-east Asia and the cyanogenic potential (CNp) of the crop as a possible food safety issue. DESIGN: We used data from the Ministry of Health in Vietnam and Statistics Authorities in Indonesia and Philippines (mean household consumption per province) to assess cassava consumption. Conversions of units were needed to facilitate the comparison of cassava consumption between countries. The most up-to-date data available regarding both cassava consumption and the CNp of cassava grown in the respective countries were assessed. SETTINGS: Vietnam, Indonesia and Philippines. PARTICIPANTS: Respondents from provinces in Vietnam (nineteen), Indonesia (thirty-three) and Philippines (eighty-one) were asked to complete a recall questionnaire detailing either the previous 24-h' or the 7-d' cassava consumption. RESULTS: Among the three countries, available data indicated that the highest median cassava-consumption figures percapita were from Indonesia and the Philippines (9·01 and 7·28 g/capita per d, respectively), with Vietnam having the least (1·14 g/capita per d). Published information regarding the CNp of cassava in the three countries was limited. CONCLUSIONS: While the findings of the present study are somewhat limited by a lack of available information regarding both the extent of cassava consumption and the CNp of cassava consumed in the three countries, it appears likely that cyanogen intake arising from cassava consumption among the three countries exceeds the FAO/WHO Provisional Maximum Tolerable Daily Intake, although any risk to public health appears limited to a minority of provinces in each country.

Worldwide overview of human infections with Hymenolepis diminuta.

Hymenolepis diminuta is a zoonotic cestode parasitizing the small intestine of rodents (definitive hosts). Humans can accidentally enter into the life cycle of this tapeworm via the ingestion of infected insects (intermediate hosts) containing cestode cysticercoids in their body cavity. More than two centuries after the first record in humans, there are no accurate estimates of the number of human cases around the world. In order to have a more precise idea about the number of human cases with H. diminuta and the current status of the disease (hymenolepiasis) worldwide, we conducted a literature review of published records on human infection with H. diminuta. One thousand five hundred and sixty-one published records of infection with H. diminuta from 80 countries were identified. This review presents an estimate of the number of human cases with H. diminuta and a current overview of the prevalence, geographic distribution, symptoms, diagnosis, exposure to infective stages, and therapeutic approaches for this underestimated zoonotic tapeworm.

Hand-Hygiene Mitigation Strategies Against Global Disease Spreading through the Air Transportation Network.

The risk for a global transmission of flu-type viruses is strengthened by the physical contact between humans and accelerated through individual mobility patterns. The Air Transportation System plays a critical role in such transmissions because it is responsible for fast and long-range human travel, while its building components-the airports-are crowded, confined areas with usually poor hygiene. Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) consider hand hygiene as the most efficient and cost-effective way to limit disease propagation. Results from clinical studies reveal the effect of hand washing on individual transmissibility of infectious diseases. However, its potential as a mitigation strategy against the global risk for a pandemic has not been fully explored. Here, we use epidemiological modeling and data-driven simulations to elucidate the role of individual engagement with hand hygiene inside airports in conjunction with human travel on the global spread of epidemics. We find that, by increasing travelers engagement with hand hygiene at all airports, a potential pandemic can be inhibited by 24% to 69%. In addition, we identify 10 airports at the core of a cost-optimal deployment of the hand-washing mitigation strategy. Increasing hand-washing rate at only those 10 influential locations, the risk of a pandemic could potentially drop by up to 37%. Our results provide evidence for the effectiveness of hand hygiene in airports on the global spread of infections that could shape the way public-health policy is implemented with respect to the overall objective of mitigating potential population health crises.

Prevalence and Antimicrobial Resistance of Salmonella in Pork, Chicken, and Duck from Retail Markets of China.

Salmonella is one of the most important foodborne pathogens associated with animal and human diseases. In this study, 672 samples of fresh meat (pork, 347; chicken, 196; and duck, 129) were collected from retail markets in different provinces of China from 2010 to 2014. We identified 10 different serotypes among 80 Salmonella isolates, whereas 12 isolates were nonmotile precluding conventional identification of complete serotype. Among these 92 isolates, Salmonella enterica serovar Derby (n = 21) was the most prevalent serotype, followed by Salmonella Enteritidis (n = 17), Salmonella Typhimurium (n = 15), Salmonella Indiana (n = 9), Salmonella Agona (n = 7), and Salmonella Assinie (n = 5). Antimicrobial resistance testing for 18 antimicrobial agents revealed that all 92 isolates were resistant to at least 1 antimicrobial agent, and 39 different resistance profiles were identified. The highest resistance was to trimethoprim-sulfamethoxazole (n = 87), followed by tetracycline (n = 51), carbenicillin (n = 38), amoxicillin/A.clav (n = 30), and piperacillin (n = 24). Our results demonstrated that meats presented a potential public health risk, thereby underlining the necessity for local regulatory enforcement agencies in China to monitor salmonellosis.

Patterns of helminth infections in Rattus rattus and Mus musculus from two Mayan communities in Mexico.

The black rat Rattus rattus and the house mouse Mus musculus are two commensal rodent species that harbour and shed zoonotic pathogens, including helminths. The aim of this survey was to study the helminth community and the patterns of infections in R. rattus and M. musculus from two Mayan communities in Mexico. Gastrointestinal helminths were isolated from 322 M. musculus and 124 R. rattus, including Gongylonema neoplasticum, Hassalstrongylus aduncus, Hassalstrongylus musculi, Hydatigera taeniaeformis metacestode, Hymenolepis diminuta, Nippostrongylus brasiliensis, Oligacanthorhynchidae gen. sp., Syphacia muris, Syphacia obvelata, Rodentolepis microstoma and Trichuris muris. The overall richness of helminths was seven in R. rattus and six in M. musculus. The results of generalized linear models showed that juvenile rodents had lower probabilities of being infected with G. neoplasticum, H. taeniaeformis and H. musculi than adult rodents. A positive association between the prevalence of S. muris and rat abundance was found. The intensity of infection with S. muris was higher in the rainy season than in the dry season; the opposite result was found for H. musculi infection. Male R. rattus harboured more S. muris specimens. The intensity of infection with T. muris was inversely associated with mouse abundance. The presence of the zoonotic H. diminuta, as well as H. taeniaeformis and R. microstoma in rodent populations indicates that there is risk of transmission, and that their entire life cycle occurs in the study area.

Metal loads and biomarker suite responses in a tropical carnivorous fish indicative of anthropogenic impacts in a Southeastern Brazilian lagoon.

Tropical coastal lagoons are highly productive environments exhibiting high biodiversity. However, the use of these ecosystems by local communities is of concern, since this generally leads to environmental degradation. The Imboassica coastal lagoon, located in Macaé city, in Northern Rio de Janeiro, is an important ecosystem in the state, however, already displaying signs of anthropogenic impacts. Carnivorous fish Hoplias malabaricus specimens were sampled from this impacted site, as well as from a reference area. Fish from Imboassica Lagoon presented lower condition factor, lower cholinesterase activity, and higher percentage of erythrocyte micronuclei when compared to fish from the reference site. Metals in fish from Imboassica Lagoon were always higher than Encantada Lagoon, with some seasonal differences, where some metals were higher in the rainy season compared to the dry season in muscle tissue, with the exception of Cu, Fe, Sr, and Zn; and in the liver, except for Ba, Cd, Cr, Ni, and Sr. Cr and Mn in the edible muscle portion of the fish were higher than the limits established by Brazilian and International legislations as permissible for human consumption, thus leading to concerns regarding public health risks for the local population that use fish as their main protein source.

Antimicrobial drug use in food-producing animals and associated human health risks: what, and how strong, is the evidence?

BACKGROUND: Antimicrobial resistance is a public health threat. Because antimicrobial consumption in food-producing animals contributes to the problem, policies restricting the inappropriate or unnecessary agricultural use of antimicrobial drugs are important. However, this link between agricultural antibiotic use and antibiotic resistance has remained contested by some, with potentially disruptive effects on efforts to move towards the judicious or prudent use of these drugs. MAIN TEXT: The goal of this review is to systematically evaluate the types of evidence available for each step in the causal pathway from antimicrobial use on farms to human public health risk, and to evaluate the strength of evidence within a 'Grades of Recommendations Assessment, Development and Evaluation'(GRADE) framework. The review clearly demonstrates that there is compelling scientific evidence available to support each step in the causal pathway, from antimicrobial use on farms to a public health burden caused by infections with resistant pathogens. Importantly, the pathogen, antimicrobial drug and treatment regimen, and general setting (e.g., feed type) can have significant impacts on how quickly resistance emerges or spreads, for how long resistance may persist after antimicrobial exposures cease, and what public health impacts may be associated with antimicrobial use on farms. Therefore an exact quantification of the public health burden attributable to antimicrobial drug use in animal agriculture compared to other sources remains challenging. CONCLUSIONS: Even though more research is needed to close existing data gaps, obtain a better understanding of how antimicrobial drugs are actually used on farms or feedlots, and quantify the risk associated with antimicrobial use in animal agriculture, these findings reinforce the need to act now and restrict antibiotic use in animal agriculture to those instances necessary to ensure the health and well-being of the animals.

Investigation on the temporal variation and source tracking of faecal bacteria in a forest dominated watershed (Comox Lake), British Columbia, Canada.

AIMS: The aims of this study were to investigate the temporal variation in Escherichia coli density and its sources at the drinking water intake of Comox Lake for a period of 3 years (2011-2013). METHODS AND RESULTS: Density of E. coli was assessed by standard membrane filtration method. Source tracking of E. coli were done by using BOX-A1R-based rep-PCR DNA fingerprinting method. Over the years, the mean E. coli density ranged from nondetectable to 9·8 CFU 100 ml(-1) . The density of E. coli in each of the years did not show any significant difference (P > 0·05); however, a comparatively higher density was observed during the fall. Wildlife was (64·28%, 153/238) identified as the major contributing source of E. coli, followed by human (18·06%, 43/238) and unknown sources (17·64%, 42/238). Although the sources were varied by year and season, over all, the predominant contributing sources were black bear, human, unknown, elk, horse and gull. CONCLUSIONS: The findings of this investigation identified the multiple animal sources contributing faecal bacteria into the drinking water intake of Comox Lake and their varying temporal occurrence. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study can reliably inform the authorities about the most vulnerable period (season) of faecal bacterial loading and their potential sources in the lake for improving risk assessment and pollution mitigation.

Plastic pollution and human pathogens: Towards a conceptual shift in risk management at bathing water and beach environments.

Emerging evidence indicates that micro- and macro-plastics present in water can support a diverse microbial community, including potential human pathogens (e.g., bacteria, viruses). This interaction raises important concerns surrounding the role and suitability of current bathing water regulations and associated pathogen exposure risk within beach environments. In response to this, we critically evaluated the available evidence on plastic-pathogen interactions and identified major gaps in knowledge. This review highlighted the need for a conceptual shift in risk management at public beaches recognising: (i) interconnected environmental risks, e.g., associations between microbial compliance parameters, potential pathogens and both contemporary and legacy plastic pollution; and (ii) an appreciation of risk of exposure to plastic co-pollutants for both water and waterside users. We present a decision-making framework to identify options to manage plastic-associated pathogen risks alongside short- and longer-term research priorities. This advance will help deliver improvements in managing plastic-associated pathogen risk, acknowledging that human exposure potential is not limited to only those who engage in water-based activity. We argue that adopting these recommendations will help create an integrated approach to managing and reducing human exposure to pathogens at bathing, recreational water and beach environments.

The role of water matrix on antibiotic resistance genes transmission in substrate layer from stormwater bioretention cells.

Recently, extensive attention has been paid to antibiotic resistance genes (ARGs) transmission. However, little available literature could be found about ARGs transmission in stormwater bioretention cells, especially the role of water matrix on ARGs transmission. Batch experiments were conducted to investigate target ARGs (blaTEM, tetR and aphA) transmission behaviors in substrate layer from stormwater bioretention cells under different water matrices, including nutrient elements (e.g., carbon, nitrogen and phosphorus), water environmental conditions (dissolved oxygen (DO), pH and salinity, etc.) and pollution factors (like heavy metals, antibiotics and disinfectants), showing that ARGs conjugation frequency increased sharply with the enhancement of water matrices (expect DO and pH), while there were obvious increasing tendencies for all ARGs transformation frequencies under only the pollution factor. The correlation between dominant bacteria and ARGs transmission implied that conjugation and transformation of ARGs were mainly determined by Firmicutes, Bacteroidota, Latescibacterota, Chloroflexi and Cyanobacteria at the phylum level, and by Sphingomonas, Ensifer, IMCC26256, Rubellimicrobium, Saccharimonadales, Vicinamibacteraceae, Nocardioides, JG30-KF-CM66 at the genus level. The mentioned dominant bacteria were responsible for intracellular reactive oxygen species (ROS) and cell membrane permeability (CMP) in the substrate layer, where the amplification of intracellular ROS variation were the largest with 144 and 147 % under the condition of TP and salinity, respectively, and the one of CMP variation were the highest more than 165 % under various pollution factors. Furthermore, both increasing DO and reducing salinity could be potential approaches for the inhibition of ARGs transmission in bioretention cells taking into account the simultaneous removal of conventional pollutants.