Sanitation By-Products Used for Lettuce (<i>Lactuca sativa</i>L.) Production: Quantitative Microbial Risk Assessment

Sanitation by-products (i.e. greywater, human urine and toilet compost) reuse for agriculture presents an opportunity to enhance food security while overcoming water scarcity and fertilizers issues in developing countries. However, the risks to health from farmers and consumers’ exposure to pathogenic micro-organisms persistent in sanitation by-products has hindered their popularity in these regions. This study was conducted to apply a quantitative microbial risk assessment to estimate the annual risk probability of Salmonella infection associated with these sanitation by-products reuse for lettuce production and explore options for health risk reduction. Risk was performed a Monte Carlo simulation for farmers and consumers. The exposure routes were contaminated soil ingestion, urine/greywater/compost ingestion and lettuce consumption without washing. Results showed that the annual infection risks of Salmonella through ingestion contaminated soil associated with urine and compost were typical scenario: 9.04 × per-person-per-year (pppy) and 2.97 × pppy, respectively, are higher than the WHO benchmark (≤1.0 × pppy). Conversely, those contaminated from greywater were 6.83 × pppy are meet the WHO benchmark. On the other hand, annual risks through lettuce consumption fertilized with urine (1.20 × pppy) were less than the risks from compost (6.20 × pppy) and greywater (7.76 × pppy). Moreover, the annual risks of infection from greywater ingestion (1.77 × pppy) exhibits a much higher risk than that urine ingestion (6.20 × pppy) approximately two orders of magnitude, and which are higher than the WHO tolerable limit of risk. The risk assessment outcomes of using sanitation by-products to lettuce production should be promoted with proper awareness of the risk by farmers and consumers.

Performance Evaluation of Two Series Vertical Flow Filters for Wastewater Treatment: A Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

This paper evaluates the efficacy of two sequential vertical flow filters (VFF), FV1 and FV2, implanted with Typha, in a pilot-scale wastewater treatment system. FV1 comprises three cells (FV1a, FV1b, and FV1c), while FV2 consists of two cells (FV2a and FV2b), each designed to reduce various physicochemical and microbiological pollutants from wastewater. Quantitative analyses show significant reductions in electrical conductivity (from 1331 to 1061 μS/cm), biochemical oxygen demand (BOD5 from 655.6 to 2.3 mg/L), chemical oxygen demand (COD from 1240 to 82.2 mg/L), total nitrogen (from 188 to 37.3 mg/L), and phosphates (from 70.9 to 14.6 mg/L). Notably, FV2 outperforms FV1, particularly in decreasing dissolved salts and BOD5 to remarkably low levels. Microbiological assessments reveal a substantial reduction in fecal coliforms, from an initial concentration of 7.5 log CFU/100mL to 3.7 log CFU/100mL, and a complete elimination of helminth eggs, achieving a 100% reduction rate in FV2. The study highlights the impact of design parameters, such as filter material, media depth, and plant species selection, on treatment outcomes. The findings suggest that the judicious choice of these components is critical for optimizing pollutant removal. For instance, different filtration materials show varying efficacies, with silex plus river gravel in FV1c achieving superior pollutant reduction rates. In conclusion, VFFs emerge as a promising solution for wastewater treatment, underscoring the importance of design optimization to enhance system efficiency. Continuous monitoring and adaptation of treatment practices are imperative to ensure water quality, allowing for safe environmental discharge or water reuse. The research advocates for ongoing improvements in wastewater treatment technologies, considering the environmental challenges of the current era. The study concludes with a call for further research to maximize the effectiveness of VFFs in water management.

Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

美国医疗废物对策的动向

1.美国医疗废物对策概况美国开始考虑治理医疗废物问题比日本早10年。在1976年修订的美国资源保护再生法(RCR Act,相当于日本的废扫法)中,要求美国环保局制定危险废物处理体系。在修订此法案的过程中,美国国会在讨论危险废物定义时,提出除了包括废物的数量、浓度或者其物理、化学性质外,还应包括带有传染性的物质。根据国会的要求,美国环保局于1978年12月在“

Developing a Questionnaire for Prediction of High Salt Intake Based on Salt Usage Behavior: Analysis from Dietary Habits and Urinary Sodium Excretion in Japan

Salt reduction policies have been implemented throughout the world as well as in Japan. However, most of the current questionnaires for estimating salt intake are apt to be based on empirical evidence. This study was aimed to develop and validate a questionnaire for predicting high salt intake based on salt usage using dietary behaviors that affect salt intake in cooperation with Niigata prefecture, Japan. The study was comprised of 760 participants aged 21 - 79 years (Men%: 49%) living in Niigata. Participants completed a questionnaire about dietary behaviors potentially relevant to salt intake. Second morning voiding urine for estimating dietary salt intake per day was collected on the same day. The relationship of estimated dietary salt intake to answers on the questionnaire was examined using analysis of covariance for age, gender, body mass index, and whether taking medication or not. Ten items on the questionnaire revealed an association with dietary salt intake per day: making oneself gorge on a meal, having ≥2 different staples per meal, having a 1-dish meal, number of simmered dishes per day, variety of pickled vegetables per day, having salt-cured fish eggs per day, quantity of soup consumed when eating noodles, preference for strong-tasting meals, frequency of eating out, and frequency of alcohol consumption.The current study identified 10 dietary behaviors that enabled the development of a salt intake questionnaire for identifying specific dietary behaviors for assessing regions and/or individuals when attempting to encourage salt reduction.

Influence of Stent Implantation on the Expression of PCNA and Apoptosis in Injured Vascular Smooth Muscle Cells

Objectives To evaluate the impact of stent implantation on proliferation and apop-tosis in injured media vascular smooth muscle cells (VSMC) and to explore the mechanism of restenosis after stent implantation. Methods Fifty male New Zealand rabbits were randomized into two groups, including balloon group and stent group. Control group was set up. The samples were harvested on 3, 7, 14, 28, 56 days after operation and the following investigation was carried out: (1) Assessing the expression of proliferating cell nuclear antigen (PCNA) of media VSMC by the method of immunohistochemistry; (2) Analyzing apoptosis of media VSMC by DNA agarose gel electrophoresis and TUNEL technique. Results The expression of PCNA and apoptosis in stent and balloon groups were markedly increased compared with control groups. (1) Stent group induced significant increased expression of PCNA in the media VSMC compared with balloon group on 3 to 28 days. On day 7, the positive rates of PCNA were 24. 36±0. 55 % vs 18. 74±1. 09 % ( P < 0. 01 ); (2) From 3 to 28 days, stent group appeared obvious DNA ladder, while balloon group only had little trace ; (3) TUNEL method showed that stent group induced much more significant apoptosis than that of balloon group on 3 to 28 days. The highest rate of apoptosis appeared on day 7: 12. 42 ±1.13% vs 5. 54±0.53% (P<0. 01); (4) By calculating the ratio of the positive rate of PCNA to apoptosis, it showed that on 3 to 28 days, the ratio of balloon group was higher than that of stent group. There was obvious difference between two groups. Conclusions Stent group induces augmented proliferation and much more significant apoptosis of media VSMC than that of balloon group. It makes the ratio of proliferation to apotosis reduced and the severity of restenosis relieved after stent implantation.

Degree of Integrated Water Resources Management Implementation in Context of Climate Change in a Watershed:Case of Oueme Basin,Benin(West Africa)

This study is based on the hypothesis that the implementation of Integrated Water Resources Management(IWRM)tools in the Oueme watershed has not led to a systematic improvement in the degree of IWRM implementation in the Oueme Valley in Benin.Methodologically,data were collected through a semi-structured survey of stakeholder families in the study area using snowball sampling.The tool used was the form developed by the United Nations to collect data to assess the level of IWRM implementation.The four(4)assessment criteria,each covering a key component of IWRM,are the enabling environment,institutions and participation,management tools and financing.The results obtained per criteria according to the stepwise methodology adopted reveal on average a degree of implementation of 40 on a scale of 0 to 100 in the Oueme basin.This value varies according to the geographical area and the factors considered.This study,which is a decision-making tool,provides a guide for governments to monitor the progress of integrated water resources management in their territory.

Impact of Paenibacillus elgii supernatant on screening bacterial strains with potential for biotechnological applications

The biotechnological industry faces a crucial demand for novel bioactive compounds,particularly antimicrobial agents,to address the rising challenge of bacterial resistance to current available antibiotics.Traditional strate-gies for cultivating naturally occurring microorganisms often limit the discovery of novel antimicrobial producers.This study presents a protocol for targeted selection of bacterial strains using the supernatant of Paenibacillus el-gii,which produces abundant signal molecules and antimicrobial peptides.Soil samples were inoculated in these enriched culture media to selectively cultivate bacteria resistant to the supernatant,indicating their potential to produce similar compounds.The bacterial strains isolated through this method were assessed for their antibac-terial activity.In addition,the functional annotation of the genome of one of these strains revealed several gene clusters of biotechnological interest.This study highlights the effectiveness of using this approach for selective cultivation of microorganisms with potential for biotechnological applications.

Distribution of PCDD/Fs in a food waste anaerobic digestion process with biogas utilization

Food waste(FW)is a major component of municipal solid waste(MSW)in developing countries such as China.Anaerobic digestion(AD)is a widely-applied FW biological treatment method following MSW classification.With FW diversion from conventional incineration plants,the environmental risk caused by trace toxic pollutants,such as polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),should be reevaluated.This study investigated a full-scale FW-AD plant in Shenzhen,China,and addressed two important underexplored issues:the distribution patterns of PCDD/Fs during the FW-AD process and PCDD/F emission characteristics of the biogas utilization exhaust gas.Mass balance demonstrated a negative balance of 2.48μg I-TEQ/t of raw FW(RFW),thus indicating that AD produced moderate PCDD/F emissions.The detailed findings were as follows:1)PCDD/F toxic equivalents(TEQs)in pure FW(RFW without impurities)were lower than in RFW,indicating that MSW source separation is crucial for decreasing the PCDD/F input into the AD system;2)PCDD/F contents(6.20–8.27 pg I-TEQ/g dry weight)in solid digestate were near the screening value of development land in China’s national standard(GB36600-2018),thus indicating that the potential environmental risk from the land application of solid digestate should be considered;and 3)PCDD/F TEQs(0.001–0.022 ng I-TEQ/Nm^(3))in biogas utilization exhaust gas were roughly equivalent to those produced by MSW incinerators in Shenzhen.This study indicated that compared with co-incineration with other waste,FW-AD will reduce PCDD/F emissions(air)from MSW incineration plants by 12.5%–21.3%at the national level under an FW separation scenario.