Of masks and methylene blue-The use of methylene blue photochemical treatment to decontaminate surgical masks contaminated with a tenacious small nonenveloped norovirus.

BACKGROUND: In the context of the SARS-CoV-2 pandemic, reuse of personal protective equipment, specifically that of medical face coverings, has been recommended. The reuse of these typically single-use only items necessitates procedures to inactivate contaminating human respiratory and gastrointestinal pathogens. We previously demonstrated decontamination of surgical masks and respirators contaminated with infectious SARS-CoV-2 and various animal coronaviruses via low concentration- and short exposure methylene blue photochemical treatment (10 µM methylene blue, 30 minutes of 12,500-lux red light or 50,000 lux white light exposure). METHODS: Here, we describe the adaptation of this protocol to the decontamination of a more resistant, non-enveloped gastrointestinal virus and demonstrate efficient photodynamic inactivation of murine norovirus, a human norovirus surrogate. RESULTS: Methylene blue photochemical treatment (100 µM methylene blue, 30 minutes of 12,500-lux red light exposure) of murine norovirus-contaminated masks reduced infectious viral titers by over four orders of magnitude on surgical mask surfaces. DISCUSSION AND CONCLUSIONS: Inactivation of a norovirus, the most difficult to inactivate of the respiratory and gastrointestinal human viruses, can predict the inactivation of any less resistant viral mask contaminant. The protocol developed here thus solidifies the position of methylene blue photochemical decontamination as an important tool in the package of practical pandemic preparedness.

Addressing personal protective equipment (PPE) decontamination: Methylene blue and light inactivates severe acute respiratory coronavirus virus 2 (SARS-CoV-2) on N95 respirators and medical masks with maintenance of integrity and fit.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has resulted in shortages of personal protective equipment (PPE), underscoring the urgent need for simple, efficient, and inexpensive methods to decontaminate masks and respirators exposed to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). We hypothesized that methylene blue (MB) photochemical treatment, which has various clinical applications, could decontaminate PPE contaminated with coronavirus. DESIGN: The 2 arms of the study included (1) PPE inoculation with coronaviruses followed by MB with light (MBL) decontamination treatment and (2) PPE treatment with MBL for 5 cycles of decontamination to determine maintenance of PPE performance. METHODS: MBL treatment was used to inactivate coronaviruses on 3 N95 filtering facepiece respirator (FFR) and 2 medical mask models. We inoculated FFR and medical mask materials with 3 coronaviruses, including SARS-CoV-2, and we treated them with 10 µM MB and exposed them to 50,000 lux of white light or 12,500 lux of red light for 30 minutes. In parallel, integrity was assessed after 5 cycles of decontamination using multiple US and international test methods, and the process was compared with the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O3) decontamination method. RESULTS: Overall, MBL robustly and consistently inactivated all 3 coronaviruses with 99.8% to >99.9% virus inactivation across all FFRs and medical masks tested. FFR and medical mask integrity was maintained after 5 cycles of MBL treatment, whereas 1 FFR model failed after 5 cycles of VHP+O3. CONCLUSIONS: MBL treatment decontaminated respirators and masks by inactivating 3 tested coronaviruses without compromising integrity through 5 cycles of decontamination. MBL decontamination is effective, is low cost, and does not require specialized equipment, making it applicable in low- to high-resource settings.

Does weight-based pricing for municipal waste collection contribute to waste reduction? A dynamic panel analysis in Flanders.

This paper analyzes the effects of weight-based pricing on municipal waste generation in Flanders (Belgium) by applying the bias-corrected least squares dummy variables estimation model to account for the dynamic relationship. The study also considers yearly weight-based pricing dummy variables to clarify the annual effects after its introducing and price elasticities of weight-based pricing systems from the both viewpoints of short and long terms. The results by the dynamic panel estimations showed that the continuous participation of weight-based pricing decreases the amount of residual waste significantly by approximately 10.4%. However, the remarkable decrease (approximately 21.4%) was observed only in the first year after the introduction and the reduction effect gradually decreases following its introduction and it disappears in five years. The study also showed that price elasticities of weight-based pricing were smaller than that of volume-based pricing for five years after its introduction and consequently the difference between them disappeared in five years. In addition, the study indicated that the estimation results by the non-dynamic fixed effects model overestimated the long-term effects in weight-based pricing and price effects while underestimating the short-term effect by its introduction. The study suggested that we should consider dynamic effects and remove the bias from the least squares dummy variables estimators when we examine the effects of weight-based pricing.

Identifying the most relevant peers for benchmarking waste management performance: A conditional directional distance Benefit-of-the-Doubt approach.

The paper demonstrates that the outcome of the robust and conditional directional distance version of the BoD model not only contains information on the overall efficiency score and rank, but also enables a region to identify its genuine peers, disentangle the overall effect of the background conditions on the performance and assess one's relative strengths and relative weakness vis-à-vis its most relevant peers when evaluating its municipal solid waste management. We illustrate how this information can be retrieved from the outcomes of DEA/BoD based efficiency and performance benchmarking studies by applying the methodology to the case of the Brussels Capital Region. The results show that Freiburg Hamburg and the province of Limburg are in general the most interesting peers for the Brussels Capital Region. In addition, the analysis reveals that Freiburg is identified as the most instructive peers if the region is interested in improving its composting and recycling rate.

Drivers of legal and illegal solid waste disposal in the Global South - The case of households in Yaoundé (Cameroon).

Managing municipal solid waste is a challenge for many policy makers, but even more so in the Global South. Regulatory instruments are often limited, available resources are scarce and illegal waste disposal is an easy opt-out. We analyze a unique dataset regarding waste disposal choices by households in Yaoundé, Cameroon, including information on illegal waste dumping. Overall, households in Yaoundé seem to act predominantly as rational, cost-minimizing agents. While social criteria also play a role, waste disposal choices are mainly determined by the accessibility of the different alternatives. In particular the output of a multinomial logit model shows that households with (easy) access to legal alternatives such as centralized drop-off containers or curbside waste collection are less likely to dispose of their waste in an illegal manner. In addition, illegal disposal becomes more attractive when the illegal waste dumpsite is closer to the family home and transportation costs are lower. Although these results might seem unspectacular, in the context of the Global South, these findings also reveal that investing in waste collection infrastructure offers great potential in improving waste disposal, particularly in combination with other measures such as removing illegal dumpsites, incorporating pre-collection and composting into institutional programs, raising awareness and increasing the level of compliance.

From pay-per-bag to pay-per-kg: The case of Flanders revisited.

Weight-based pricing systems for municipal solid waste collection and processing are increasingly popular in many European countries and regions. However, the impact on waste generation of such pricing schedules remains debated and depends strongly on the practical details of the system used. This article assesses the impact of a voluntary transition by Flemish municipalities from the default price-per-bag pricing systems to a more sophisticated weight-based pricing schedule. By (1) exploiting alternative statistical techniques, (2) using more recent data and (3) focusing on the introduction effect of the new pricing schedule, we are able to complement and refine prior research on this topic. Our results indicate that introducing weight-based pricing has initially a significant and substantial downward impact on the amount of residual municipal solid waste per capita. This result is robust under different methodologies that control for selection bias. There are however, indications that this initial effect does not persist in the years after introduction.

Waste pricing policies and cost-efficiency in municipal waste services: the case of Flanders.

Major changes in municipal solid waste (MSW)-related services, such as the collection system, often require important initial investments, while the benefits on the output side typically occur over a longer time perspective. However, when analyzing the association between such policy choices and cost efficiency of MSW collection and disposal, the time horizon is often not taken into account. This article advocates the use of the Malmquist Productivity Index approach to measure and analyze cost efficiency changes over time after the introduction of the relative new weight-based waste collection and billing system in Flanders. The results and robustness checks indicate that introducing weight-based pricing does not lead to lower cost efficiency of MSW service provision.

Evaluating the efficiency of municipalities in collecting and processing municipal solid waste: a shared input DEA-model.

This paper proposed an adjusted "shared-input" version of the popular efficiency measurement technique Data Envelopment Analysis (DEA) that enables evaluating municipality waste collection and processing performances in settings in which one input (waste costs) is shared among treatment efforts of multiple municipal solid waste fractions. The main advantage of this version of DEA is that it not only provides an estimate of the municipalities overall cost efficiency but also estimates of the municipalities' cost efficiency in the treatment of the different fractions of municipal solid waste (MSW). To illustrate the practical usefulness of the shared input DEA-model, we apply the model to data on 293 municipalities in Flanders, Belgium, for the year 2008.

Wasteful waste-reducing policies? The impact of waste reduction policy instruments on collection and processing costs of municipal solid waste.

We study the impact of some local policies aimed at municipal solid waste (MSW) reduction on the cost efficiency of MSW collection and disposal. We explicitly account for differences between municipalities in background conditions by using a bootstrapped version of the Data Envelopment Analysis methodology in combination with a matching technique. Using data on 299 municipalities in Flanders, Belgium, for the year 2003, our results indicate that municipalities that are member of a waste collection joint venture, or that subscribe to a voluntary agreement to reduce MSW at the highest ambition level, collect and process MSW more efficiently than other municipalities. Weekly instead of two-weekly waste collection, or using a weight-based pricing system appears to have no impact on efficiency. Our results show that aiming at MSW reduction does not lead to lower efficiency of public service provision, even on the contrary.

Residual household waste: from pay-per-bag to pay-per-kilogram. An evaluation study for Flanders.

To be in line with the polluter-pays principle, an increasing number of Flemish municipalities have introduced a weight-based pricing system for residual household waste. Municipalities using this new pricing scheme are keen to ascribe decreasing waste production to the introduction of the new system. In order to evaluate the real impact of the weight-based pricing, an extension to the standard difference-in-differences evaluation techniques is proposed. The main idea is to use historical observations on waste production to determine which version of the difference-in-differences technique is most suitable to assess the impact of a policy action on waste quantities. The method is easy to apply, which makes it a very useful tool for both scientists and policy makers. Surprisingly, empirical results for Flanders indicate that, on average, municipalities using the weight-based system do not perform better than other municipalities.

Assessing the effectiveness of voluntary solid waste reduction policies: methodology and a Flemish case study.

The purpose of this paper is to illustrate the use of statistical techniques to evaluate the effectiveness of voluntary policy instruments for waste management. The voluntary character of these instruments implies that latent characteristics, unobserved by the analyst, might influence the subscription decision and might lead to biased estimates of the effectiveness of the policy instrument if standard techniques are used. We propose an extension of the difference-in-differences (DiD) estimator to evaluate the effectiveness of voluntary policy instruments, which is termed the dynamic difference-in-differences (or DDD) estimator. We illustrate the technique by estimating the effectiveness of voluntary cooperation agreements between the Flemish environmental administration and individual municipalities aimed at curbing residential solid waste. Using a dataset covering all 308 Flemish municipalities for the period 2000-2005, our results indicate that municipalities subscribing to the agreement accomplished less reduction of their waste levels compared to what could be expected on the basis of their own performance prior to subscription and the performance of the non-subscribers. This result might be explained by the rising marginal cost of extra residential solid waste reduction policies. In addition, there are indications that subscribing municipalities refrain from additional reduction efforts once the target waste level of the program is achieved. The more complicated DDD methodology is shown to generate additional insight over the ordinary DiD analysis.