Hygiene and environmental health advances最新文献

Human excreta can be used as biofertilizers due to their nutrient and organic matter content. Nevertheless, the behavior of microorganisms should be investigated, as enteric pathogens can accumulate in the soil. Therefore, we evaluated the survival and transport of two enteric bacteria (E. coli and Salmonella enterica) and two enteric virus surrogates (MS2 and ΦX-174 bacteriophages) when applied as contaminants of four biofertilizers on Lactuca sativa production. The study was carried out in lysimeters outdoors with repacked silt loam soil, using a randomized block design (RBD) with six treatments and three replicates. Biofertilizers were urea-treated feces, feces composted with organic waste, stored liquid urine, and struvite and were inoculated at 10⁶–10⁷ cfu/pfu g⁻¹ of E. coli and bacteriophages strains and 10⁷–10⁹ of S. enterica. Soil amended with composted feces exhibited the lowest decimal reductions (T₉₀) for the microorganisms evaluated, with 10.2 days for E. coli, 11.9 days for S. enterica, 22.2 days for MS2, and 3.7 days for ΦX-174. Urea-treated feces temporarily hindered the growth and survival of E. coli and S. enterica in the soil. However, both bacteria were present after one month, while MS2 showed a stable concentration with this biofertilizer. E. coli presented a stable behavior when applied with urine, whereas MS2 was stable with urea-treated feces, urine, and struvite. ΦX-174 and S. enterica were not considered good representatives of most resistant enteric pathogens’ behavior in the soil during food production since they were not detected in leachate and showed a rapid die-off in soil. E. coli leached faster and in higher concentrations than MS2, which presented higher concentrations in deeper soil layers, from 10 to 20 cm. Therefore, using urine, struvite, and urea-treated faces implied a higher chance of infection, as a decimal reduction time was not observed during the 36 days of the experiment. As a result, in short-term cultures, it is recommended that additional hygiene barriers are taken to avoid infection since E. coli and MS2 were still detected at the end of the experiment. An interval of 90 days between fertilizing and harvesting is recommended to prevent pathogen infection. These results are the basis for a quantitative risk assessment of human excreta-based biofertilizers for food production.

Due to climate change precipitation patterns are changing in terms of frequency and quantity in Germany. As a result, prolonged dry weather can lead to extremely low flow rates in river systems with large portions of treated wastewater. However, storm events and heavy rainfall events are increasing too, which may lead to higher frequencies of combined sewer overflows. Increased microbial pollution (e.g. coliform bacteria, clostridia, faecal streptococci) of waterbodies after heavy precipitation events was demonstrated in several studies. Pathogenic multi-resistant bacteria enter waterbodies via sewer systems. The persistence potential of such pathogens in aquatic environments is mainly still unknown. This study investigated the growth behaviour of Gram-negative extended spectrum beta-Lactamase-producing Klebsiella oxytoca and Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus in river water. The concentrations of these antibiotic-resistant bacteria were monitored in batch experiments using river water differently impacted by wastewater. Staphylococcus aureus persisted for at least 3 days at incubation temperatures of 8 and 18 °C. The persistence of K. oxytoca and E. coli was shown for at least 37 days at both temperatures. In the river water at 8 °C, bacteria concentrations decreased slower, suggesting diminished persistence of ARB (antibiotic-resistant bacteria) with increasing temperatures. Initial concentrations of ARB and other pathogens in river water corresponded to the impact of wastewater. However, significant effects on the persistence itself by wastewater impact could not be shown for the bacteria species tested. Further studies should pursue our approaches concerning the persistence of pathogenic ARB in freshwater to assess the health risk for humans and animals.

Background

Health risk assessment based on epidemiological data for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are evidenced. Whereas information about health-based guidance values (HBGVs) and health risk for Chinese population related to PFOS and PFOA is scarce.

Objectives

To provide candidate HBGVs for PFOS and PFOA based on Chinese epidemiological data and assess the health risk related to excessive exposure.

Methods

We reviewed scientific literature and collected available original data from epidemiological studies conducted in China. Critical endpoints and data were selected and used in benchmark dose (BMD) analysis to obtain lower confidence limits of BMD (BMDLs) of PFOS and PFOA. Physiologically based pharmacokinetic (PBPK) models were applied to calculate the point of departure (PODs) for PFOS and PFOA, which led to the determination of the HBGVs for the said chemicals. Margin of exposure (MOE) method was used to evaluate the health risk of population based on exposure data among Chinese and HBGVs.

Results

Alanine aminotransferase (ALT), total cholesterol (TC) and birth weight (BW) were selected as critical endpoints. Epidemiological data from 4,224 adults, 2,153 paired mother-newborn, 2,518 newborns, 439 pregnant women and 733 children in China were included in this study. BMDLs and PODs for PFOS are varied while BMDLs for PFOA were similar. PODs for PFOS (1.56 ng/kg/day) and PFOA (1.52 ng/kg/day) based on BW using National Birth Cohort Study were selected as HBGVs. Most MOEs for PFOS and PFOA among Chinese population were larger than 1 and smaller than 100, indicating moderate concern. Around 16% MOEs for PFOS were smaller than 1, implying high concern.

Conclusion

The HBGVs for PFOS and PFOA were 1.56 ng/kg/day and 1.52 ng/kg/day, respectively. Health risk of Chinese population related to PFOS and PFOA exposure should be concerned and more studies should be conducted to evaluate the risk of the chemicals.

An unexpected rise in dengue cases has overwhelmed hospitals in Pakistan. Floods and intense monsoon rain have affected almost 33 million people since June 2022. Heavy monsoon rains may be a result of rising water temperatures. Dengue poses a severe risk to public health globally and to countries affected by floods, particularly Pakistan and the whole Indian subcontinent. Pakistan's expanding urban and agricultural economies place it at a higher risk for contracting vector-borne diseases.

Background

Intimate partner violence (IPV) against women is a serious problem in many developing countries. Longer distance traveled to access water services may affect women's ability to meet domestic obligations and results in violence. However, the associations between times spent by women to access water services and intimate partner violence against women in Sub-Saharan Africa (SSA) remain unknown.

Methods

We used population-based data collected from demographic and health surveys (DHS) in 26 SSA, to examine the associations between round-trip time to water sources and IPV. We estimated round-trip time to water sources based on the self-reported experience of women through their time spent collecting water during the period of 2008 and 2020 as presented in the DHS surveys. Primary outcomes were all self-reported and were derived from the DHS questionnaires about IPV, especially physical violence. We categorized IPV into two groups (Severe and less severe IPV). Respondents who reported being kicked, strangled, threatened with a knife/gun or other weapons by their husbands, or hurt were pooled together and labelled as having experienced severe IPV. Those who claimed to have been pushed, had their arms twisted, or had their hair pulled were grouped and classified as less severe forms of violence. Multivariable logistic regression was performed by fitting crude models and adjusted models. We also conducted a sensitivity analysis, stratification, and country-specific analysis to examine the contributions of these factors to the associations between round-trip time to water sources and IPV. The estimated results are presented as an odds ratio (OR) and their 95% confidence interval (CI).

Results

A total of 14,714 (11.2%) women faced severe IPV and 38,222 (28.9%) faced less severe IPV. Results showed that a 30 min increase in round-trip fetching time was associated with an increase in severe IPV and the crude OR was 1.06 (95% CI: 1.05, 1.07) for all 26 countries. After adjusting for covariates, the association of round-trip time to water sources and severe IPV remained positive and significant with an OR of 1.03 (95% CI: 1.01, 1.05). Furthermore, there were positive and significant associations between round-trip time and less severe IPV before and after adjusting for covariates. There were positive associations between round-trip time to basic access to water sources and severe IPV with an OR of 1.08 (95% CI: 1.05, 1.10). For potential effect modifiers, our results revealed disparities in IPV estimates stratified by husbands who consumed alcohol, level of education of husbands, and age of respective women. There were differences in the estimates between countries, the largest increment in severe IPV was observed in Comoros, Sierra Leone, and Namibia.

Conclusions

This cross-sectional study provides persuasive evidence for the association between round-trip tim