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1.

Background

In rural China ~607 million people drink boiled water, yet little is known about prevailing household water treatment (HWT) methods or their effectiveness. Boiling, the most common HWT method globally, is microbiologically effective, but household air pollution (HAP) from burning solid fuels causes cardiovascular and respiratory disease, and black carbon emissions exacerbate climate change. Boiled water is also easily re-contaminated. Our study was designed to identify the HWT methods used in rural China and to evaluate their effectiveness.

Methods

We used a geographically stratified cross-sectional design in rural Guangxi Province to collect survey data from 450 households in the summer of 2013. Household drinking water samples were collected and assayed for Thermotolerant Coliforms (TTC), and physicochemical analyses were conducted for village drinking water sources. In the winter of 2013–2104, we surveyed 120 additional households and used remote sensors to corroborate self-reported boiling data.

Findings

Our HWT prevalence estimates were: 27.1% boiling with electric kettles, 20.3% boiling with pots, 34.4% purchasing bottled water, and 18.2% drinking untreated water (for these analyses we treated bottled water as a HWT method). Households using electric kettles had the lowest concentrations of TTC (73% lower than households drinking untreated water). Multilevel mixed-effects regression analyses showed that electric kettles were associated with the largest Log10TTC reduction (-0.60, p<0.001), followed by bottled water (-0.45, p<0.001) and pots (-0.44, p<0.01). Compared to households drinking untreated water, electric kettle users also had the lowest risk of having TTC detected in their drinking water (risk ratio, RR = 0.49, 0.34–0.70, p<0.001), followed by bottled water users (RR = 0.70, 0.53–0.93, p<0.05) and households boiling with pots (RR = 0.74, 0.54–1.02, p = 0.06).

Conclusion

As far as we are aware, this is the first HWT-focused study in China, and the first to quantify the comparative advantage of boiling with electric kettles over pots. Our results suggest that electric kettles could be used to rapidly expand safe drinking water access and reduce HAP exposure in rural China.  相似文献   

2.
Household water treatment, including boiling, chlorination and filtration, has been shown effective in improving drinking water quality and preventing diarrheal disease among vulnerable populations. We used a case-control study design to evaluate the extent to which the commercial promotion of household water filters through microfinance institutions to women's self-help group (SHG) members improved access to safe drinking water. This pilot program achieved a 9.8% adoption rate among women targeted for adoption. Data from surveys and assays of fecal contamination (thermotolerant coliforms, TTC) of drinking water samples (source and household) were analyzed from 281 filter adopters and 247 non-adopters exposed to the program; 251 non-SHG members were also surveyed. While adopters were more likely than non-adopters to have children under 5 years, they were also more educated, less poor, more likely to have access to improved water supplies, and more likely to have previously used a water filter. Adopters had lower levels of fecal contamination of household drinking water than non-adopters, even among those non-adopters who treated their water by boiling or using traditional ceramic filters. Nevertheless, one-third of water samples from adopter households exceeded 100 TTC/100ml (high risk), and more than a quarter of the filters had no stored treated water available when visited by an investigator, raising concerns about correct, consistent use. In addition, the poorest adopters were less likely to see improvements in their water quality. Comparisons of SHG and non-SHG members suggest similar demographic characteristics, indicating SHG members are an appropriate target group for this promotion campaign. However, in order to increase the potential for health gains, future programs will need to increase uptake, particularly among the poorest households who are most susceptible to disease morbidity and mortality, and focus on strategies to improve the correct, consistent and sustained use of these water treatment products.  相似文献   

3.
Background: Compared to adults, children maybe more highly exposed to toxic substances in drinking water because they consume more water per unit of body weight. The U.S. Environmental Protection Agency (USEPA) has developed new guidance for selecting age groups and age-specific exposure factors for assessing children's exposures and risks to environmental contaminants. Research Aim: To demonstrate the application and importance of applying age-specific drinking water intake rates, health reference values, and exposure scenarios when assessing drinking water exposures because these approaches illustrate the potential for greater potential for adverse health effects among children. Methods: manganese, an essential nutrient and neurotoxicant, was selected as a case study and chemical of potential concern for children's health. A screening-level risk assessment was performed using age-specific drinking water intake rates and manganese concentrations from U.S. public drinking water systems. Results: When age-specific drinking water intake rates are used to calculate dose, formula-fed infants receive the highest dose of manganese from drinking water compared to all other age groups. Estimated hazard quotients suggest adverse health effects are possible. Use of USEPA's standardized childhood age groups and childhood exposure factors significantly improves the understanding of childhood exposure and risks.  相似文献   

4.
通过野外实地考察结合遥感技术手段开展珠海市三灶区城市水土流失重点调查。三灶区水土流失类型以人为侵蚀为主,主要是由开发平台建设、取土采石和修筑公路造成,侵蚀类型复杂多样,多沿交通道路两侧以及城市建成区周遍地带分布,侵蚀模数相差很大,最大侵蚀模数和最小侵蚀模数之间相差3个数量级,充分反映了城市水土流失的特点。  相似文献   

5.
通过野外实地考察结合遥感技术手段开展珠海市三灶区城市水土流失重点调查。三灶区水土流失类型以人为侵蚀为主 ,主要是由于开发平台建设、取土采石和修筑公路造成 ,侵蚀类型复杂多样 ,多沿交通道路两侧以及城市建成区周遍地带分布 ,侵蚀模数相差很大 ,最大侵蚀模数和最小侵蚀模数之间相差 3个数量级 ,充分反映了城市水土流失的特点。  相似文献   

6.
India, like many other developed and developing countries, has adopted an extended producer responsibility (EPR) approach for electronic waste (e‐waste) management under its E‐waste (Management and Handling) Rules, 2011. Under these rules, producers have been made responsible for setting up collection centers of e‐waste and financing and organizing a system for environmentally sound management of e‐waste. In this article, we use the implementation of these rules in Ahmedabad in western India as a case study to conduct a critical analysis of the implementation of India's Rules. Interviews of main stakeholder groups, including a sample of regulated commercial establishments, regulatory agencies enforcing the Rules, informal actors involved in waste collection and handling, as well as publicly available information on the implementation constitute data for our case study. Our results indicate that while there has been an increase in the formal waste processing capacity after the implementation of the Rules, only 5% to 15% of the total waste generated is likely channeled through formal processing facilities. While the EPR regulation forced the producers to take action on a few relatively inexpensive aspects of the Rules, the collection and recycling system has not been made convenient for the consumers to deposit e‐waste in formal collection and recycling centers. Based on our findings, we argue that Indian EPR regulation should go beyond simple take‐back mandates and consider implementing other policy instruments such as a deposit‐refund system. An important implication for developing countries is the need for careful attention to instrument choice and design within EPR regulations.  相似文献   

7.
Increased demand for water and energy and growing recognition of environmental issues motivate awareness of how these resources are used in industry. Industrial tomato processing consumes substantial quantities of both water and energy. To understand how these resources are used in tomato processing and what opportunities exist for improving efficiency, a water energy nexus (WEN) assessment was conducted that accounted for the various ways energy becomes embedded in water during processing by motors, pumps, fans, and boilers. The WEN assessment was conducted at an industrial tomato processing facility that processed 265 metric tonnes of fruit per hour to develop a map of water and associated energy use at each processing step. A total of 1.29 billion kilograms (kg) of water were used for the processing season, with 870 million kg routed to flumes. The analysis identified the thermal energy used to generate steam for the various heat exchangers and evaporators used during processing as the greatest source of embedded energy in process water (778,000 gigajoules per season). The electrical energy embedded in the process water totaled 4.4 million kilowatt‐hours per season, over 80% of which was attributed to pumping. Moreover, the data were used to identify opportunities to improve efficiency by adjusting water loads on equipment and developing strategies for water and energy conservation and recovery. The baseline water and energy use data provided by the WEN assessment can enable additional modeling to assess resource efficiency measures and the life cycle impact of processed tomato products.  相似文献   

8.
Large-scale irrigation practices may disturb local hydrologic cycles and distribute trace metals throughout the environment. Reported here is the spatial pattern of trace metals and associated health risks in an agricultural area of China, which has a long history of irrigation with water from the Yellow River. Multivariate statistical analyses and a risk-assessment model were employed to interpret the environmental data. It indicated that Zn, Se, B, Ba, Fe, Mn, Mo, Ni, V, Al, Li, Sr, Be, Cd, Cr, Cu, and Pb were all detected in the surface waters. Compared to drinking water guidelines, the primary trace metal pollution components (Al, Fe, Se, B, Mn, and Zn) exceeded drinking water standards by 40.7%, 14.8%, 29.6%, 25.9%, 11.1%, and 14.8%, respectively. Except for one site that exhibited anomalous metal concentrations, landscape features of trace metals identified a uniform distribution of trace metals for all sample sites. The calculated mean value of Hazard Quotients (HQs) exceeded the USEPA's recommendations by a factor of 2.9 times the threshold value. Primary sources of trace metals were associated with natural deposition, industrial and agrochemical processes, and a mixed source of both geogenic and anthropogenic origins.  相似文献   

9.
《PloS one》2013,8(12)

Background

Climate change potentially has important effects on distribution, abundance, transmission and virulence of parasites in wild populations of animals.

Methodology/Principal Finding

Here we analyzed paired information on 89 parasite populations for 24 species of bird hosts some years ago and again in 2010 with an average interval of 10 years. The parasite taxa included protozoa, feather parasites, diptera, ticks, mites and fleas. We investigated whether change in abundance and prevalence of parasites was related to change in body condition, reproduction and population size of hosts. We conducted analyses based on the entire dataset, but also on a restricted dataset with intervals between study years being 5–15 years. Parasite abundance increased over time when restricting the analyses to datasets with an interval of 5–15 years, with no significant effect of changes in temperature at the time of breeding among study sites. Changes in host body condition and clutch size were related to change in temperature between first and second study year. In addition, changes in clutch size, brood size and body condition of hosts were correlated with change in abundance of parasites. Finally, changes in population size of hosts were not significantly related to changes in abundance of parasites or their prevalence.

Conclusions/Significance

Climate change is associated with a general increase in parasite abundance. Variation in laying date depended on locality and was associated with latitude while body condition of hosts was associated with a change in temperature. Because clutch size, brood size and body condition were associated with change in parasitism, these results suggest that parasites, perhaps mediated through the indirect effects of temperature, may affect fecundity and condition of their hosts. The conclusions were particularly in accordance with predictions when the restricted dataset with intervals of 5–15 years was used, suggesting that short intervals may bias findings.  相似文献   

10.

Background

Travel time and distance are barriers to care for HIV-infected children in rural sub-Saharan Africa. Decentralization of care is one strategy to scale-up access to antiretroviral therapy (ART), but few programs have been evaluated. We compared outcomes for children receiving care in mobile and hospital-affiliated HIV clinics in rural Zambia.

Methods

Outcomes were measured within an ongoing cohort study of HIV-infected children seeking care at Macha Hospital, Zambia from 2007 to 2012. Children in the outreach clinic group received care from the Macha HIV clinic and transferred to one of three outreach clinics. Children in the hospital-affiliated clinic group received care at Macha HIV clinic and reported Macha Hospital as the nearest healthcare facility.

Results

Seventy-seven children transferred to the outreach clinics and were included in the analysis. Travel time to the outreach clinics was significantly shorter and fewer caretakers used public transportation, resulting in lower transportation costs and fewer obstacles accessing the clinic. Some caretakers and health care providers reported inferior quality of service provision at the outreach clinics. Sixty-eight children received ART at the outreach clinics and were compared to 41 children in the hospital-affiliated clinic group. At ART initiation, median age, weight-for-age z-scores (WAZ) and CD4+ T-cell percentages were similar for children in the hospital-affiliated and outreach clinic groups. Children in both groups experienced similar increases in WAZ and CD4+ T-cell percentages.

Conclusions

HIV care and treatment can be effectively delivered to HIV-infected children at rural health centers through mobile ART teams, removing potential barriers to uptake and retention. Outreach teams should be supported to increase access to HIV care and treatment in rural areas.  相似文献   

11.
12.

Background

In the northwest of Ethiopia, at the South Gondar region, there was a visceral leishmaniasis (VL) outbreak in 2005, making the disease a public health concern for the regional health authorities ever since. The knowledge on how the population perceives the disease is essential in order to propose successful control strategies.

Methodology/Principal findings

Two surveys on VL knowledge, attitudes and practices were conducted at the beginning (May 2009) and at the end (February 2011) of a VL longitudinal study carried out in rural communities of Libo Kemkem and Fogera, two districts of the Amhara Regional State. Results showed that VL global knowledge was very low in the area, and that it improved substantially in the period studied. Specifically, from 2009 to 2011, the frequency of proper knowledge regarding VL signs and symptoms increased from 47% to 71% (p<0.0001), knowledge of VL causes increased from 8% to 25% (p<0.0001), and knowledge on VL protection measures from 16% to 55% (p<0.0001). Moreover, the improvement observed in VL knowledge was more marked among the families with no previous history of VL case. Finally, in 2011 more than 90% of the households owned at least an impregnated bed net and had been sprayed, and attitudes towards these and other protective measures were very positive (over 94% acceptance for all of them).

Conclusions/Significance

In 2009 the level of knowledge regarding VL was very low among the rural population of this area, although it improved substantially in the study period, probably due to the contribution of many actors in the area. VL patients and relatives should be appropriately informed and trained as they may act as successful health community agents. VL risk behavioural patterns are subject to change as attitudes towards protective measures were very positive overall.  相似文献   

13.

Background

Tuberculosis (TB) is global health concern and a leading infectious cause of mortality. Reversing TB incidence and disease-related mortality is a major global health priority. Infectious disease mortality is directly linked to failure to adhere to treatments. Using technology to send reminders by short message services have been shown to improve treatment adherence. However, few studies have examined tuberculosis patient perceptions and attitudes towards using SMS technology to increase treatment adherence. In this study, we sought to investigate perceptions related to feasibility and acceptability of using text messaging to improve treatment adherence among adults who were receiving treatment for TB in Callao, Peru.

Methods

We conducted focus group qualitative interviews with current TB positive and non-contagious participants to understand the attitudes, perceptions, and feasibility of using short message service (SMS) reminders to improve TB treatment adherence. Subjects receiving care through the National TB Program were recruited through public health centers in Ventanilla, Callao, Peru. In four focus groups, we interviewed 16 patients. All interviews were recorded and transcribed verbatim. Thematic network analysis and codebook techniques were used to analyze data.

Results

Three major themes emerged from the data: limits on health literacy and information posed challenges to successful TB treatment adherence, treatment motivation at times facilitated adherence to TB treatment, and acceptability of SMS including positive perceptions of SMS to improve TB treatment adherence. The majority of patients shared considerations about how to effectively and confidentially administer an SMS intervention with TB positive participants.

Conclusion

The overall perceptions of the use of SMS were positive and indicated that SMS technology may be an efficient way to transmit motivational texts on treatment, health education information, and simple reminders to increase treatment adherence for low-income TB patients living in Peru.  相似文献   

14.
Hedonic pricing analysis is conducted to determine the implicit values of various attributes in the market value of a good. In this study, hedonic pricing analysis was applied to measure the contribution of grain quality search and experience attributes to the price of rice in two rural towns in the Philippines. Rice samples from respondents underwent quantitative routine assessments of grain quality. In particular, gelatinization temperature and chalkiness, two parameters that are normally assessed through visual scores, were evaluated by purely quantitative means (differential scanning calorimetry and by digital image analysis). Results indicate that rice consumed by respondents had mainly similar physical and chemical grain quality attributes. The respondents’ revealed preferences were typical of what has been previously reported for Filipino rice consumers. Hedonic regression analyses showed that grain quality characteristics that affected price varied by income class. Some of the traits or socioeconomic factors that affected price were percent broken grains, gel consistency, and household per capita rice consumption. There is an income effect on rice price and the characteristics that affect price vary between income classes.  相似文献   

15.

Background

Carbon credits are an increasingly prevalent market-based mechanism used to subsidize household water treatment technologies (HWT). This involves generating credits through the reduction of carbon emissions from boiling water by providing a technology that reduces greenhouse gas emissions linked to climate change. Proponents claim this process delivers health and environmental benefits by providing clean drinking water and reducing greenhouse gases. Selling carbon credits associated with HWT projects requires rigorous monitoring to ensure households are using the HWT and achieving the desired benefits of the device. Critics have suggested that the technologies provide neither the benefits of clean water nor reduced emissions. This study explores the perspectives of carbon credit and water, sanitation and hygiene (WASH) experts on HWT carbon credit projects.

Methods

Thirteen semi-structured, in-depth interviews were conducted with key informants from the WASH and carbon credit development sectors. The interviews explored perceptions of the two groups with respect to the procedures applied in the Gold Standard methodology for trading Voluntary Emission Reduction (VER) credits.

Results

Agreement among the WASH and carbon credit experts existed for the concept of suppressed demand and parameters in the baseline water boiling test. Key differences, however, existed. WASH experts’ responses highlighted a focus on objectively verifiable data for monitoring carbon projects while carbon credit experts called for contextualizing observed data with the need for flexibility and balancing financial viability with quality assurance.

Conclusions

Carbon credit projects have the potential to become an important financing mechanism for clean energy in low- and middle-income countries. Based on this research we recommend that more effort be placed on building consensus on the underlying assumptions for obtaining carbon credits from HWT projects, as well as the approved methods for monitoring correct and consistent use of the HWT technologies in order to support public health impacts.  相似文献   

16.
Over the past two decades, watershed restoration has dramatically increased internationally. California has been at the forefront, allocating billions of dollars to restoration activities through legislation and voter-approved bonds. Yet, the implications of restoration remain ambiguous because there has been little examination of restoration accomplishments and almost no analysis of the political context of restoration. This article addresses these gaps, utilizing a case study of the Russian River basin in Northern California. We identify trends that shed light on both the ecological and the political implications of restoration at a basin scale by examining a database of 787 restoration projects implemented in the Russian River basin since the early 1980s. Although a total of over $47 million has been spent on restoration in the basin, dominant forms of restoration are limited in scope to small-scale projects that focus on technical solutions to site-specific problems. The majority of restoration efforts are devoted to road repair, riparian stabilization, and in-stream structures, accounting for 62% of all projects. These types of projects do not address the broader social drivers of watershed change such as land and water uses. We suggest that restoration can become more effective by addressing the entire watershed as a combination of social and ecological forces that interact to produce watershed conditions.  相似文献   

17.
There is a surge in chronic diseases in the developing world, driven by a high prevalence of cardio-metabolic risk factors. This study described differences in prevalence of obesity and cardio-metabolic risk factors between urban and rural settlements in the Ashanti Region of Ghana. This comparative cross-sectional study included 672 participants (median age 50 years), of which 312 were from Kumasi (urban) and 360 from Jachie-Pramso (rural). Demographic, anthropometric and other cardio-metabolic risk factors were gathered and venous blood samples were drawn for biochemical assays. Results suggested significant differences in diastolic blood pressure (80.0 mmHg vs 79.5 mmHg; p = 0.0078), and fasting blood sugar (5.0 mmo/l vs 4.5 mmol/l; p < 0.0001) between the two groups. Further differences in anthropometric measures suggested greater adiposity amongst participants in the urban area. Participants in the urban area were more likely than rural participants, to have high total cholesterol and LDL-c (p < 0.0001 respectively). Risk factors including BMI ≥ 25 (p < 0.0001), BMI ≥ 30 (p < 0.0001), high waist circumference (p < 0.0001), high waist-to-height ratio (p < 0.0001) and alcohol consumption (p = 0.0186) were more prevalent amongst participants in the urban area. Markers of adiposity were higher amongst females than males in both areas (p < 0.05). In the urban area, hypertension, diabetes and lifestyle risk factors were more prevalent amongst males than females. Differences in risk factors by urban / rural residence remained significant after adjusting for gender and age. Obesity and cardio-metabolic risk factors are more prevalent amongst urban settlers, highlighting an urgent need to avert the rise of diet and lifestyle-related chronic diseases.  相似文献   

18.
The so called chromosome preparation is a procedure consisting of three strictly connected stages that enables to obtain chromosomes of quality suitable for cytogenetic analysis. Interestingly, experimental evidence strongly suggested that chromosome spreading and swelling (key processes that allow their counting and detailed structural analysis) are induced in the last fixative-evaporation stage by the interaction, mediated by acetic acid, between water from the environmental humidity, and the cytoplasmic matrix and the chromatin. However, since a considerable variation in the quality of chromosome preparations is observed, strongly depending on the environmental conditions in which the procedure takes place, a better comprehension of the mechanisms underlying chromosome preparation is required. To this aim, here we analysed intact lymphocytes before and at each stage of the chromosome preparation protocol by Fourier transform infrared (FTIR) spectroscopy, a technique widely used for the study not only of isolated biomolecules, but also of complex biological systems, such as whole cells. Interestingly, we found that the chromosome preparation protocol induces significant structural changes of cell proteins and DNA, in particular due to the interaction with acetic acid. Moreover, noteworthy, through the monitoring of changes in the water combination band between 2300 and 1800 cm–1, we provided evidence at molecular level of the crucial role of the bound water to the cytoplasmic matrix and to the chromatin in determining the chromosome spreading and swelling. Our FTIR results, therefore, underline the need to perform the last fixative-evaporation stage in standardized and optimized temperature and relative humidity conditions, thus providing chromosomes of high quality for the cytogenetic analysis that would lead in this way to more reliable results.Key words: Chromosome preparation, chromosome spreading and swelling, DNA conformational transition, FTIR (micro)spectroscopy, protein, DNA hydration  相似文献   

19.
The cluster patterns of multilamellar vesicles (MLV) of dimyristoylphosphatidylcholine (DMPC) were analyzed using a combination of fractal analysis and lattice simulation. Self-assembly of DMPC MLVs resulted in two types of microscopically observable clusters. The clusters were classified on the basis of their mass fractal dimension, two-dimensional porosity, and the light scattering properties. Spectrin, a cytoskeletal protein, well known for its role in determining the cellular morphology, was used to perturb such spontaneously formed clusters. The fragmentation of the clusters by hydrodynamic perturbation followed a power law, implying again a fractal behavior. A lattice-based simulation was performed generating different class of cluster patterns. The observed correspondence between the cluster patterns and their stability was discussed in the framework of the proposed lattice simulation.  相似文献   

20.
Campylobacter infection is a leading cause of bacterial gastroenteritis worldwide, and most clinical cases appear as isolated, sporadic infections for which the source is rarely apparent. From July 2005 to December 2007 we conducted a prospective case-case study of sporadic, domestically-acquired Campylobacter enteritis in rural versus urban areas and a prevalence study of Campylobacter in animal and environmental sources in the Eastern Townships, Quebec. Isolates were typed using Multilocus Sequence Typing (MLST) to reinforce the case-case findings and to assign a source probability estimate for each human isolate. The risk of human campylobacteriosis was 1.89-fold higher in rural than urban areas. Unconditional multivariate logistic regression analysis identified two independent risk factors associated with human Campylobacter infections acquired in rural area: occupational exposure to animals (OR = 10.6, 95% CI: 1.2–91, p = 0.032), and household water coming from a private well (OR = 8.3, 95% CI: 3.4–20.4, p<0.0001). A total of 851 C. jejuni isolates (178 human, 257 chicken, 87 bovine, 266 water, 63 wild bird) were typed using MLST. Among human isolates, the incidence rates of clonal complexes (CC) CC-21, CC-45, and CC-61 were higher in rural than urban areas. MLST-based source attribution analysis indicated that 64.5% of human C. jejuni isolates were attributable to chicken, followed by cattle (25.8%), water (7.4%), and wild birds (2.3%). Chicken was the attributable source for the majority of cases, independent of residential area, sex and age. The increased incidence in rural compared to urban areas was associated with occupational exposure to animals, particularly cattle among those aged 15–34 years, and with consumption of private well water. Both bovine and water exposure appeared to contribute to the seasonal variation in campylobacteriosis. These results provide a basis for developing public education and preventive programs targeting the risk factors identified.  相似文献   

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