Verónica Corella-Barud

Survival of fecal coliforms in dry-composting toilets

ABSTRACT The dry-composting toilet, which uses neither water nor sewage infrastructure, is a practical solution in areas with inadequate sewage disposal and where water is limited. These systems are becoming increasingly popular and are promoted to sanitize human excreta and to recycle them into fertilizer for nonedible plants, yet there are few data on the safety of this technology. This study analyzed fecal coliform reduction in approximately 90 prefabricated, dry-composting toilets (Sistema Integral de Reciclamiento de Desechos Orgánicos [SIRDOs]) that were installed on the U.S.-Mexico border in Ciudad Juárez, Chihuahua, Mexico. The purpose of this study was to determine fecal coliform reduction over time and the most probable method of this reduction. Biosolid waste samples were collected and analyzed at approximately 3 and 6 months and were classified based on U.S. Environmental Protection Agency standards. Results showed that class A compost (high grade) was present in only 35.8% of SIRDOs after 6 months. The primary mechanism for fecal coliform reduction was found to be desiccation rather than biodegradation. There was a significant correlation (P = 0.008) between classification rating and percent moisture categories of the biosolid samples: drier samples had a greater proportion of class A samples. Solar exposure was critical for maximal class A biosolid end products (P= 0.001). This study only addressed fecal coliforms as an indicator organism, and further research is necessary to determine the safety of composting toilets with respect to other pathogenic microorganisms, some of which are more resistant to desiccation.

Peri-urbanization and in-home environmental health risks: the side effects of planned and unplanned growth.

Urbanization is occurring at an explosive rate, and many cities, especially in low-income countries, are struggling to control growth and stop the development of unplanned communities. This research investigates the in-home environmental health risks associated with planned and unplanned growth in peri-urban communities (neighborhoods) of a rapidly growing city in Northern Mexico. Surveys were conducted during home visits to 98 households in a planned community and 202 households in unplanned communities of comparable, though slightly higher, socio-economic status. To assess the differences for the two types of communities, multiple risk factors were measured and compared. Results showed that households in both planned and unplanned communities were vulnerable to poor environmental health conditions, but more risk factors and negative health outcomes were associated with unplanned communities. Some of the obvious benefits of living in a planned community included better-constructed homes and water and sewer connections. Other study results indicated that households in the planned community reported fewer cases of respiratory problems (P = 0.039) and dizziness (P = 0.009). They were also less likely to store insecticides and other chemicals inappropriately in their home (P < 0.001). Providing adequate housing infrastructure appears to provide a number of important benefits to health and behavior beyond the simple provision of additional amenities in the home.

Entertainment‐education and CO poisonings in ciudad Juárez: A case study of El Asesino invisible

Abstract Residents in peri‐urban, low‐income colonias from Ciudad Juárez, México, are at high risk for carbon monoxide (CO) intoxication from the use of unvented, indoor heaters. To address this risk, a comic book‐style communication protocol was developed using the mental models approach and the entertainment‐education (EE) communication strategy to help colonia residents properly use this home heating method. El Asesino Invisible (The Invisible Assassin) encouraged people to buy a CO alarm for the home and provided information about CO intoxication. Part of a larger research agenda, the health campaign data were gathered from residents in colonias where high levels of indoor CO were previously measured. The essay provides an overview of the EE process and related strategies for reaching low‐income, colonia audiences. Limitations are addressed and ideas for future research are provided.

Evaluation of neighborhood treatment systems for potable water supply.

Piped water is available in Ciudad Juárez, Chihuahua, México, but residual disinfectant is not reliably found in the public drinking water supply. Lack of confidence in the public supply leads many residents to rely on bottled water. To provide consistent disinfection, two health clinics were equipped with ultraviolet disinfection systems, and neighboring households were encouraged to obtain their drinking water from the treatment systems. Use of the treated water declined from 62% of self-selected study participants at the time of the first visit to 40% at the second visit. During the first visit, diarrhea prevalence was similar among households using treated water and other water sources yet diarrhea prevalence was higher among households using the treated water during the second visit. Microbiological quality of the treated water in the homes was not demonstrably superior to that of other sources.

Evaluation of waterless sanitation for hot arid climates

Ecological sanitation systems are of particular interest in hot arid climates where water is in short supply. This article compares the effectiveness of dehydrating and biodegrading toilets in reducing pathogenic microorganisms in human waste.