Contribution of different land use catchments on the microplastic pollution in detention basin sediments

The assessment of microplastic (MP) pollution in urban areas is essential considering its abundance in freshwater, particularly due to urban wet weather discharge. The precise sources of MPs must be identified to better understand its characteristics. This study examines the relationship between MP pollution in detention basin sediments and land use in the investigated catchments. The study of stormwater management infrastructure, mainly in detention basins, has enabled the quantification of MP abundance in sediments conveyed by stormwater in urban areas. Sediment sampling was conducted in ten detention basins and one combined sewer overflow (CSO) structure in the Lyon metropolitan area, France. These basins correspond to stormwater outlets of representative urban catchment areas. MP extraction involves densimetric separation and organic matter degradation. MPs were then characterized using micro-Fourier infrared spectroscopy and siMPle software. This protocol identified MPs between 50 and 500 μm in the study sites. This study highlights the high abundance in the collected sediment samples, ranging from 2,525 to 1,218,82 MP kg-1 by dry weight sediment. The MPs found have a median size around 115 μm, making them very small MPs that are mainly composed of polypropylene followed by polyethylene and polystyrene or polyethylene terephthalate. The abundance of MPs in sediments is associated with the land use type. Catchments in predominantly industrial and commercial zones were more significantly polluted with MPs compared with those in predominantly agricultural or heterogeneous zones. Finally, statistical analyses revealed links between sedimentary and urban parameters and MPs concentrations. Several recommendations are given for future research, notably concerning the analyzing of stormwater sediments to understand the sources of MP pollution.

Bacterial assemblages of urban microbiomes mobilized by runoff waters match land use typologies and harbor core species involved in pollutant degradation and opportunistic human infections

Cities are patchworks of urban catchments divided into functional units according to their commercial, residential and industrial activities, and socio-urbanistic patterns. The hypothesis of city surface microbiomes being structured by socio-urbanistic variables leading to an emergence of synurbic taxa was tested. According to the r/K microbial ecology theory, a gradient of well-adapted synurbic K-strategists and of opportunistic -r-strategists should occur over city surfaces. K-strategists would be core components while r-ones would be transiently detected. To resolve these patterns, sub-catchments (n = 21) of an area of high commercial and industrial activities were investigated over three time periods covering one year. The sub-catchments' land use patterns and associated human behaviors were converted into socio-urbanistic variables and groupings. Bacterial cells mobilized by runoffs per sub-catchment were recovered, and analyzed by classical approaches, microbial source tracking DNA assays and DNA meta-barcoding approaches. Relationships between these datasets, the runoff physico-chemical properties, and descriptors of the socio-urbanistic groupings were investigated. 16S rRNA meta-barcoding analyses showed evidence of the occurrence of K- and r-like strategists. Twenty-eight core genera were identified, and correlation networks revealed large bacterial modules organized around actinobacterial taxa involved in hydrocarbon degradation processes. Other bacterial networks were related to the occurrences of hygienic wastes, and involved bacteria originating from fecal contaminations. Several r-strategists like Sulfurospirillum were recorded and found associated to point source pollutions. The tpm-metabarcoding approach deciphered these r / K strategists at the species level among more than ten genera. Nine core K-like Pseudomomas species were identified. The P. aeruginosa human opportunistic pathogen and P. syringae phytopathogens were part of these K-strategists. Other tpm-harboring bacterial pathogens showed r-like opportunistic distribution patterns. Correlation network analyses indicated a strong incidence of hygienic wastes and hydrocarbon-pollutions on tpm-harboring bacteria. These analyses demonstrated the occurrence of core synurbic bacterial K-strategists over city surfaces.

Ecotoxicological risk assessment of contaminants of emerging concern identified by "suspect screening" from urban wastewater treatment plant effluents at a territorial scale

Urban wastewater treatment plants (WWTP) are a major vector of highly ecotoxic contaminants of emerging concern (CECs) for urban and sub-urban streams. Ecotoxicological risk assessments (ERAs) provide essential information to public environmental authorities. Nevertheless, ERAs are mainly performed at very local scale (one or few WWTPs) and on pre-selected list of CECs. To cope with these limits, the present study aims to develop a territorial-scale ERA on CECs previously identified by a "suspect screening" analytical approach (LC-QToF-MS) and quantified in the effluents of 10 WWTPs of a highly urbanized territory during three periods of the year. Among CECs, this work focused on pharmaceutical residue and pesticides. ERA was conducted following two complementary methods: (1) a single substance approach, based on the calculation for each CEC of risk quotients (RQs) by the ratio of Predicted Environmental Concentration (PEC) and Predicted No Effect Concentration (PNEC), and (2) mixture risk assessment ("cocktail effect") based on a concentration addition model (CA), summing individual RQs. Chemical results led to an ERA for 41 CEC (37 pharmaceuticals and 4 pesticides) detected in treated effluents. Single substance ERA identified 19 CECs implicated in at least one significant risk for streams, with significant risks for DEET, diclofenac, lidocaine, atenolol, terbutryn, atorvastatin, methocarbamol, and venlafaxine (RQs reaching 39.84, 62.10, 125.58, 179.11, 348.24, 509.27, 1509.71 and 3097.37, respectively). Mixture ERA allowed the identification of a risk (RQmix > 1) for 9 of the 10 WWTPs studied. It was also remarked that CECs leading individually to a negligible risk could imply a significant risk in a mixture. Finally, the territorial ERA showed a diversity of risk situations, with the highest concerns for 3 WWTPs: the 2 biggest of the territory discharging into a large French river, the Rhône, and for the smallest WWTP that releases into a small intermittent stream.

Incentives to patients versus incentives to health care providers: The users' perspective

In theory, health care providers may adapt their professional behavior to the financial incentives resulting from their remuneration. Our research question is whether the users of health care services anticipate such behavior from their general practitioner (GP) and, if they do, what consequences such anticipation has on their preferences regarding financial incentives. Our theoretical model explains users' preferences for one or another incentives scheme, disentangling the financial motives (incentives amounts, wealth) from the behavioral ones (perceived GPs' sensitivity to incentives). We empirically test our theoretical predictions using data from a survey that elicits individual preferences for either patient or provider hypothetical incentives in France. The empirical results confirm the theoretical ones: users tend to prefer incentives to patients rather than to GPs when the amount of GP incentives is high, when the amount of patient incentives is low, when they anticipate that their GP's medical decisions are affected by financial incentives or when their wealth is high. Otherwise, they prefer their GP to face financial incentives.

Private forest owners motivations for adopting biodiversity-related protection programs

Since economic incentives are typically fairly low for many non-industrial private forest owners, it is of interest for public policy to examine whether other motives might play a role on adoption of Biodiversity-related Protection Programs. In a survey of non-industrial private forest owners, a number of current programs, that include biodiversity protection to some degree, are investigated: Prosilva, environmental associations, other programs of forest management. Across the survey, adoption amounts to 22% for all the programs jointly, and is shown to depend on economic, social and intrinsic motives, with significant crowding-out only between the economic and intrinsic motives, that is, intrinsic motives likely lessen the effectiveness of economic incentives. That does not occur with social motives; these results constitute a test of the "reputational crowding-out" theory of Bénabou and Tirole, (2006). Adoption of any program is strongly negatively correlated to the others. Nearly no respondent adopted the Natura 2000 program.

Urban domestic wastewater: how to reduce individual injection?

The present paper aims to identify ways to reduce pollution injected by residents in the urban wastewater network system. Two approaches are considered. The first one uses flow and pollutant calculation to test whether a polluter can easily be identified in a neighborhood. The second approach uses a survey to examine what incentive would be most effective to influence residents' behavior. Hydrodynamic simulation results show that concentration profiles at the network outlet corresponding to all possible polluters are similar and thus do not point out specific resident source of pollution. Household-level survey results show that most socio-economic and public-good-related characteristics do not play a significant role in explaining choices to discard in the home wastewater network. Apart from the nature of the waste itself, by far the belief that the respondent has about neighbors' and relatives' discarding behavior is the main driver of the choice.