Incidence of and risk factors for skin ailments among farmers working with wastewater-fed agriculture in Hanoi, Vietnam

Occupational Hazards Faced by Inland Fishers of Odisha State, India

OBJECTIVE

To identify occupational hazards and hazard control strategies adopted by inland fishers of Odisha state in India.

METHODS

Information on occupational hazards faced by fishers was collected by personal interviews with 90 riverine and reservoir fishers of Odisha. Through qualitative discussions with key informants and review of literature, a list of occupational hazards were prepared and classified into physical, ergonomics, psychosocial, and natural. Responses were quantified, and descriptive statistics were used for data analysis.

RESULTS

Occupational hazards faced by fishers were physical (94%), ergonomic (75%), psychosocial (50%), and natural (34%) in nature. Physical hazards include sharp fishing instruments, uneven surfaces, high temperatures, and wet/slippery areas on the vessel along with the presence of snake/leech/crocodile/fish fin rays. About 97% of reservoir and 90% of the riverine fishers reported physical hazards leading to cuts, fractures, dehydration, headache, sunburn, snakebite, leech bite, crocodile bite, and injuries due to fish fin rays. Heavy nature of work and force exerting activities caused pain in the upper back (50%), shoulders (45%), and lower back (41%). Regarding psychosocial hazard, stress (31%), and anxiety (23%) was reported. Common reasons for this were uncertainty in fish catch and extended working hours, causing tiredness, headache, dizziness, and fatigue. Natural hazards like cyclones, floods, and excessive rain caused financial loss and damage to fishing nets and boats. Regarding personal protective equipment (PPE), floating buoys were used by 26% of riverine and 43% of reservoir fishers to avoid drowning.

CONCLUSION

Occupational hazards in the inland fishing sector were identified as physical, ergonomic, psychosocial, and natural. No particular hazard control strategy was reported to be used. Integrating the occupational safety measures in the fisheries policies is thus needed.

Quantitative microbial risk assessment (QMRA) for setting health-based performance targets during soil aquifer treatment

A quantitative microbial risk assessment was conducted to assess the health risks associated with the exposure of agricultural workers to tertiary treated wastewater in irrigated fields through soil ingestion in Cyprus. Three pathogenic microorganisms were chosen, particularly E. coli (bacteria), rotavirus (viruses) and Cryptosporidium. Two extreme exposure scenarios were investigated. Monte Carlo simulations were performed using input data from literature, and the model outputs were compared to the health standards of the World Health Organization (WHO). The results suggested that additional treatment is required for all pathogens to satisfy the health standards. Sensitivity analysis identified the source concentration and pathogen reduction due to soil aquifer passage as the most influential factors in the model outputs. Additional computations were performed to evaluate the minimum pathogen reduction due to soil aquifer passage so that the health targets are achieved for the 95 % of the output values. Rotavirus and Cryptosporidium were found to require more treatment than E. coli. The inclusion of these reference pathogens to the monitoring network of the local authorities is recommended, and the role of soil aquifer passage is emphasized on reducing the concentration of the contaminants.

The food-water quality nexus in periurban aquacultures downstream of Bangkok, Thailand

Peri-urban aquacultures produce nutritious food in proximity to markets, but poor surface water quality in rapidly expanding megacities threatens their success in emerging economies. Our study compared, for a wide range of parameters, water quality downstream of Bangkok with aquaculture regulations and standards. For parameters not meeting those requirements, we sought to establish whether aquaculture practice or external factors were responsible. We applied conventional and advanced methods, including micropollutant analysis, genetic markers, and 16S rRNA amplicon sequencing, to investigate three family-owned aquacultures spanning extensive, semi-intensive and intensive practices. Canals draining the city of Bangkok did not meet quality standards for water to be used in aquaculture, and were sources for faecal coliforms, Bacteriodes, Prevotella, Human E. coli, tetracycline resistance genes, and nitrogen into the aquaculture ponds. Because of these inputs, aquacultures suffered algae blooms, with and without fertilizer and feed addition to the ponds. The aquacultures were sources of salinity and the herbicide diuron into the canals. Diuron was detectable in shrimp, but not at a level of concern to human health. Given the extent and nature of pollution, peri-urban water policy should prioritize charging for urban wastewater treatment over water fees for small-scale agricultural users. The extensive aquaculture attenuated per year an estimated twenty population equivalents of nitrogen pollution and trillions of faecal coliform bacteria inputs from the canal. Extensive aquacultures could thus contribute to peri-urban blue-green infrastructures providing ecosystem services to the urban population such as flood risk management, food production and water pollution attenuation.

Scoping Global Aquaculture Occupational Safety and Health

Objectives: In 2017 the Food and Agriculture Organization (FAO) Committee on Fisheries committed to prioritize occupational safety and health issues in aquaculture (AOSH). An international team was established to synthesize OSH knowledge concerning more than 19 million, often vulnerable, aquaculture workers found globally.Methods: The study was conducted as a desktop scoping exercise using both peer-reviewed and gray literature and the knowledge and expertize of an international panel. Collated information used a standard proforma. Panel members developed draft national and regional AOSH profiles outlining occupational hazards contributing to occupational injuries, diseases, and known solutions. These were work-shopped and refined after gathering additional information and used to compile the first global scoping review report on AOSH.Results: Synthesized results revealed multiple hazards, significant global knowledge gaps and some successful and unsuccessful global, national and industry-specific AOSH policies, practices and standards along the primary supply chain, in marine and freshwater contexts. Some constructive initiatives by the International Labor Organization (ILO) and FAO, industry, labor and civil society groups in a range of employment and geographical settings and across diverse populations of workers were identified.Conclusion: Global commitment to AOSH should be given the same focus as product quality, biosecurity, food safety and environmental sustainability in the sector. This needs development and implementation of integrated AOSH actions appropriate for diverse settings especially in low and middle-income countries encompassing greater uptake of international codes, better risk assessment and OSH management, adoption of technological innovations, effective OSH regulation and enforcement, adequate resources, training and information.

Epidemiological Evidence and Health Risks Associated With Agricultural Reuse of Partially Treated and Untreated Wastewater: A Review

The use of partially treated and untreated wastewater for irrigation is beneficial in agriculture but may be associated with human health risks. Reports from different locations globally have linked microbial outbreaks with agricultural reuse of wastewater. This article reviews the epidemiological evidence and health risks associated with this practice, aiming toward evidence-based conclusions. Exposure pathways that were addressed in this review included those relevant to agricultural workers and their families, consumers of crops, and residents close to areas irrigated with wastewater (partially treated or untreated). A meta-analysis gave an overall odds ratio of 1.65 (95% CI: 1.31, 2.06) for diarrheal disease and 5.49 (95% CI: 2.49, 12.10) for helminth infections for exposed agricultural workers and family members. The risks were higher among children and immunocompromised individuals than in immunocompetent adults. Predominantly skin and intestinal infections were prevalent among individuals infected mainly via occupational exposure and ingestion. Food-borne outbreaks as a result of crops (fruits and vegetables) irrigated with partially or untreated wastewater have been widely reported. Contamination of crops with enteric viruses, fecal coliforms, and bacterial pathogens, parasites including soil-transmitted helminthes (STHs), as well as occurrence of antibiotic residues and antibiotic resistance genes (ARGs) have also been evidenced. The antibiotic residues and ARGs may get internalized in crops along with pathogens and may select for antibiotic resistance, exert ecotoxicity, and lead to bioaccumulation in aquatic organisms with high risk quotient (RQ). Appropriate mitigation lies in adhering to existing guidelines such as the World Health Organization wastewater reuse guidelines and to Sanitation Safety Plans (SSPs). Additionally, improvement in hygiene practices will also provide measures against adverse health impacts.

Health risks from exposure to untreated wastewater used for irrigation in the Mezquital Valley, Mexico: A 25-year update

Wastewater reuse for agriculture is common worldwide; wastewater treatment, however, is rare in many countries, leading to high potential for exposure to harmful pathogens. Mexico City, one of the largest producers of untreated wastewater for agricultural use worldwide, was the site of key epidemiologic studies conducted in the 1990s. We both reviewed the literature on and conducted a cross-sectional study of diarrheal risk and wastewater contamination to provide an updated assessment of health risks and to inform an upcoming update of the 2006 WHO guidelines on wastewater reuse. We surveyed communities in the Mezquital Valley that use wastewater for irrigation and communities that use well water to compare the prevalence of self-reported diarrheal disease in children under five years old. Wastewater, well water, household environmental samples, and stool samples were collected and analyzed. Communities exposed to wastewater had a higher one-week prevalence of diarrhea (10%) compared to unexposed communities (5%). This association remained in an adjusted modified Poisson regression model (PR = 2.31, 95% CI 1.00, 5.31), but not when limited to households engaged in agriculture. Water quality indicators document differences between irrigation water from the two community groups. These results are in agreement with 25 population studies identified by our review that were conducted since or not included in the 2006 WHO guidelines and show consistent negative impacts of wastewater exposure on health. While overall diarrheal prevalence has declined when compared to studies conducted over 25 years ago in the same region, the association of diarrheal disease and wastewater exposure has remained and possibly increased. With rising urbanization worldwide, attention to these risks and wastewater treatment is becoming increasingly important.

Intestinal parasite infections and associated risk factors in communities exposed to wastewater in urban and peri-urban transition zones in Hanoi, Vietnam

Background

Infections with intestinal parasites (helminths and intestinal protozoa) are endemic in Southeast Asia and inappropriate management and reuse of wastewater might exacerbate the risk of human infections. In rapidly growing urban settings, little is known about the extent of intestinal parasite infections. We assessed the point-prevalence and risk factors of intestinal parasite infections in population groups differently exposed to wastewater in urban and peri-urban transition zones in Hanoi, the capital of Vietnam.

Methods

A cross-sectional survey was carried out between April and June 2014 in people aged ≥ 18 years at risk of wastewater exposure from To Lich River: workers maintaining wastewater treatment facilities; urban farmers reusing wastewater; and urban dwellers at risk of flooding events. For comparison, two peri-urban population groups living in close proximity to the Red River were chosen: farmers using river water for irrigation purposes; and people living in the same communities. A single stool sample was subjected to Kato-Katz and formalin-ether concentration methods for the diagnosis of helminth and intestinal protozoa infections. A questionnaire was administered to determine risk factors and self-reported signs and symptoms.

Results

A total of 681 individuals had complete data records. Highest point-prevalence rates of intestinal parasite infections were observed for peri-urban farmers (30 %). Hookworm and Trichuris trichiura were the predominant helminth species (25 % and 5 %, respectively). Peri-urban farmers were at higher odds of infection with intestinal parasites than any other groups (adjusted odds ratio 5.8, 95 % confidence interval 2.5 to 13.7). Lack of access to improved sanitation and not receiving deworming within the past 12 months were associated with higher infection risk, while higher educational attainment and socioeconomic status were negatively associated with intestinal parasite infections.

Conclusions

Our results suggest that exposure to wastewater was not directly associated with infection with helminths and intestinal protozoa in different population groups in Hanoi. These findings might be explained by a high level of awareness of health risks and access to safe sanitary infrastructure in urban areas. The high prevalence rates observed in peri-urban farmers call for specific interventions targeting this population group.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1809-6) contains supplementary material, which is available to authorized users.

A Review of Health Risks and Pathways for Exposure to Wastewater Use in Agriculture

BACKGROUND

Wastewater is increasingly being used in the agricultural sector to cope with the depletion of freshwater resources as well as water stress linked to changing climate conditions. As wastewater irrigation expands, research focusing on the human health risks is critical because exposure to a range of contaminants must be weighed with the benefits to food security, nutrition and livelihoods.

OBJECTIVES

The goal of this paper was to review research examining health risks and exposure pathways associated with wastewater irrigation to identify research trends and gaps.

METHODS

We conducted a review of the literature and identified a total of 126 studies published from 1995 to 2013. Findings were summarized based on several themes including types of exposure pathways, wastewater contaminants, methodological approaches and the geographical distribution of research.

RESULTS

Only 23 studies used epidemiological methods, while most research applied alternative methods to estimate risk, such as quantitative risk assessment models or comparisons of crop contamination to established guidelines for wastewater reuse. A geographic breakdown demonstrated a focus on microbiological contaminants in specific regions such as sub-Saharan Africa and Southeast Asia, despite growing chemical risks associated with rapid urbanization and industrialization that may change the types and distribution of wastewater contaminants.

CONCLUSIONS

To provide a more comprehensive understanding of the health risks of wastewater use in agriculture, future research should consider multiple exposure routes, long-term health implications, and increase the range of contaminants studied, particularly in regions heavily dependent on wastewater irrigation.

CITATION

Dickin SK, Schuster-Wallace CJ, Qadir M, Pizzacalla K. 2016. A review of health risks and pathways for exposure to wastewater use in agriculture. Environ Health Perspect 124:900-909; http://dx.doi.org/10.1289/ehp.1509995.

Evidence for Public Health Risks of Wastewater and Excreta Management Practices in Southeast Asia: A Scoping Review

The use of wastewater and excreta in agriculture is a common practice in Southeast Asia; however, concerns remain about the potential public health risks of this practice. We undertook a scoping review to examine the extent, range, and nature of literature, as well as synthesize the evidence for associations between wastewater and excreta management practices and public health risks in Southeast Asia. Three electronic databases (PubMed, CAB Direct, and Web of Science) were searched and a total of 27 relevant studies were included and evaluated. The available evidence suggested that possible occupational health risks of wastewater and excreta management practices include diarrhea, skin infection, parasitic infection, bacterial infection, and epilepsy. Community members can be at risk for adverse health outcomes through consuming contaminated fish, vegetables, or fruits. Results suggested that practices including handling, treatment, and use of waste may be harmful to human health, particularly farmer’s health. Many studies in this review, however, had limitations including lack of gender analyses, exposure assessment, and longitudinal study designs. These findings suggest that more studies on identifying, quantitatively assessing, and mitigating health risks are needed if sustainable benefits are to be obtained from wastewater and excreta reuse in agriculture in Southeast Asia.

Investigation on the Trace Elemental Profile of Sewage Workers in Kolkata, an Indian Megacity

Background

Environmental pollution has become a global health risk. Exposure to pollutants at the work place, i.e. occupational exposure, is one of the areas that need immediate attention. The civic drainage workers are exposed to pollutants present in the wastewater they handle and most of them are toxic heavy metals. Exposure to such pollutants may be a health hazard, since it can lead to the imbalance in nutrient elements status.

Design and Methods

In the present study, profiling of trace elements in the blood of drainage worker population from an Indian megacity, Kolkata, was carried out by energy dispersive x-ray fluorescence (EDXRF) and compared with the control group population of the same area.

Results

The elements detected by EDXRF spectrometry include P, S, Cl, K, Fe, Cu, Zn, Se, Br, and Rb. By using ANOVA with 5% significance level, we observed significant alterations in the trace elements status, iron over loading, selenium deficiency, and in Cu-Zn ratio. Gender specific variations within the same population were also observed.

Conclusions

The results indicate that the drainage workers have altered elemental profile in comparison to that of control population.

Gender in occupational health research of farmworkers: a systematic review

Background

Farmwork is one of the most hazardous occupations for men and women. Research suggests sex/gender shapes hazardous workplace exposures and outcomes for farmworkers. This paper reviews the occupational health literature on farmworkers, assessing how gender is treated and interpreted in exposure-outcome studies.

Methods

The paper evaluates peer-reviewed articles on men and women farmworkers' health published between 2000 and 2012 in PubMed or SCOPUS. Articles were identified and analyzed for approaches toward sampling, data analysis, and use of exposure indicators in relation to sex/gender.

Results

18% of articles reported on and interpreted sex/gender differences in health outcomes and exposures. Sex/gender dynamics often shaped health outcomes, yet adequate data was not collected on established sex/gender risk factors relating to study outcomes.

Conclusion

Research can better incorporate sex/gender analysis into design, analytical and interpretive approaches to better explore its mediation of health outcomes in light of emerging calls to mainstream gender research. Am. J. Ind. Med. 57:1344–1367, 2014. © 2014 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals, Inc. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Genotoxicity Study with Special Reference to Comet Test in the Blood Cells of Workers Exposed to Sewage Water

Awareness among sewage workers to occupational exposure is growing slowly in many developing countries. Lead (Pb) and cadmium (Cd) are present in sewage water and workers are exposed to these metals as a result of unprotected handling. These heavy metals exposures are responsible for DNA damage and lowering blood total iron (Fe) concentration. Zinc (Zn) is an element for promoting metallothionine expression and binds the free Cd. The total suspended solids (TSS), total dissolved solids (TDS), Pb, and Cd were estimated in sewage water. The whole blood Zn and Fe concentration and Pd and Cd were also estimated. Genotoxicity as indicated by DNA damage was studied by comet assay. It was observed that there were significant differences (P<0.001) of Pb and Cd concentration in blood for the sewage workers when compared with control population. DNA damage was also observed to be significantly (P<0.001) higher in the exposed groups but their blood Fe concentration was significantly lower, which may be the reason for their tendency for retention of blood Cd and make them more susceptible. This study also indicated that aged workers had higher blood Zn concentrations as compared to the younger (working < 20 years) workers. This may indicate a possible adaptive response. The present study proposes that younger (working < 20 years) group is more susceptible as compared to aged group (working > 20 years).

A foodborne outbreak of enterotoxigenicE. coliandSalmonellaAnatum infection after a high-school dinner in Denmark, November 2006

In industrialized countries enterotoxigenicEscherichia coli(ETEC) is mainly diagnosed as a cause of travellers' diarrhoea, but it is also known to cause foodborne outbreaks. We report an outbreak of acute gastroenteritis caused by ETEC serotypes O92:H−and O153:H2 as well asSalmonellaAnatum, which affected around 200 students and teachers after a high-school dinner in Greater Copenhagen, Denmark, November 2006. A retrospective cohort study showed that consumption of pasta salad with pesto was associated with an increased risk of illness (attack rate 59·4%; risk ratio 2·6, 95% confidence interval 1·2–5·7). Imported fresh basil used for preparation of the pesto was the most likely source of contamination. Although ETEC is associated with travellers' diarrhoea in Denmark, this outbreak suggests that a proportion of sporadic ETEC infections might be caused by contaminated imported foodstuffs. To improve food safety further, it is important to target this poorly regulated and researched area.

Dermatitis among farmers engaged in peri-urban aquatic food production in Hanoi, Vietnam

OBJECTIVE

To assess whether exposure to wastewater is a risk factor for dermatitis (eczema) among farmers engaged in peri-urban aquatic food production in Hanoi, Vietnam.

METHODS

A cross-sectional study with two follow-ups was conducted from April to December 2005 in two peri-urban communes in Hanoi, one using wastewater and another using river, rain and well water for aquatic food production. In each commune, 100 households were randomly selected and adult household members engaged in farming field work were interviewed in three surveys. Farmers who reported skin problems at the time of interviews were examined and treated by a dermatologist. Data were analysed for one farmer per household.

RESULTS

The overall prevalence of dermatitis from 592 interviews was 6.3%. The commune which used wastewater had a much higher overall prevalence of dermatitis (10.4%) than the commune that did not (2.1%; P-value < 0.001). Multivariable logistic regression analyses showed that occupational wastewater contact was an important risk factor for dermatitis (odds ratio [OR] 3.0; 95% confidence interval [CI] 1.1-7.7). Duration of daily wastewater contact was not significantly associated with dermatitis. Aquaculture work in the wet season carried an increased risk of dermatitis in both communes (OR 2.8; 95% CI 1.02-7.6). The use of personal protective measures during field work and washing hands and feet after work did not reduce the risk for dermatitis. However, observations showed that these practices were applied in such a way that they were unlikely to provide effective protection against wastewater contact.

CONCLUSION

Contact with wastewater is an important risk factor for dermatitis among farmers engaged in wastewater-fed peri-urban aquatic food production. Additional studies should test preventive and mitigating measures such as improved personal protection and hygiene.

Helminth infections among people using wastewater and human excreta in peri-urban agriculture and aquaculture in Hanoi, Vietnam

OBJECTIVE

To assess the prevalence of helminth infections and their associated risks in a community using both wastewater and human excreta in agriculture and aquaculture.

METHODS

A cross-sectional study was conducted in a peri-urban area in Hanoi, Vietnam. Data on the demography, socioeconomics and sanitation were collected from a survey of 400 agricultural households. Parasitological examination for the eggs of Ascaris sp., Trichuris sp. and hookworm was performed on single stool specimens obtained from study household members' 15-70 years and 0-72 months of age.

RESULTS

Of 807 stool samples collected from 620 adults and 187 children, 39% were infected with helminths. The prevalence of infections with Ascaris sp., Trichuris sp. and hookworm was 21.6%, 9.8% and 21.8%, respectively. Univariate and multivariate analyses showed that being an adult, female gender, living in a household without a latrine, excreta composted for less than 1 month and use of fresh human excreta were significantly associated with co-infection with all three helminths. Being an adult was an independent determinant for infections with individual helminths. The absence of a latrine and use of stored urine for irrigation were associated with an increased risk of Ascaris infection. Risk factors for Trichuris infection were inadequately composted excreta and year-round wastewater contact; risk factors for hookworm infection were female gender, household without a latrine and use of fresh human excreta.

CONCLUSION

Wastewater exposure did not pose a major risk for helminth infection in this community. Instead, lack of sanitation facilities and use of fresh or inadequately composted human excreta in agriculture were important risk factors.

Skin disease among farmers using wastewater in rice cultivation in Nam Dinh, Vietnam

OBJECTIVE

To assess the risk of skin disease among farmers occupationally exposed to wastewater.

METHODS

One-year follow-up study with monthly assessments of wastewater exposure and skin disease in Nam Dinh, northern Vietnam, in two adjacent communes with contrasting levels of wastewater use. In each commune, 200 households were randomly selected.

RESULTS

Of the 1103 individuals aged > or =15 years, 381 reported a skin problem at baseline or at any of the monthly visits, primarily dermatitis (eczema) and superficial fungal infections. Among the 874 subjects who were free from skin disease at baseline and who could be followed up > or =11 months, 183 developed a new skin disease (cumulative incidence 21%). Exposure to wastewater was a major risk factor for skin disease with a relative risk (RR) of 1.89 [95% confidence interval (CI) 1.39-2.57] in multivariable analysis. Other risk factors for skin disease were involvement in agriculture in general (RR = 2.59, 95% CI 1.11-6.02), flower cultivation (RR = 1.36, 95% CI 1.01-1.83), vegetable farming (RR = 1.47, 95% CI 1.04-2.08), and a history of eczema (RR = 1.47, 95% CI 1.05-2.05).

CONCLUSION

Exposure to wastewater is a major risk factor for skin disease. In future studies, an attempt should be made to link specific chemical or biological agents in the wastewater to specific skin diseases.