Death by heat: the Chulli treatment system

The chulli system is an innovative technology for household treatment of microbiologically contaminated water. A metal coil is built into a traditional clay oven, and during cooking events water is passed through the coil, raising the effluent temperature to at least 60° C and effectively pasteurizing the water. The capital costs are low, and no additional time or fuel is required to treat the water. Although first developed for use in arsenicaffected areas of Bangladesh, it is now finding wider application in coastal areas affected by cyclone Sidr, where surface water is the main source of drinking water

Beyond improved: monitoring drinking water in the post-MDG era

The MDGs have been a major driver of public policy in the water and sanitation sectors. The indicators used to measure progress towards MDG Target 7c are based on a technological classification of water and sanitation infrastructure into ‘improved’ and ‘unimproved’ classes. While this classification has been useful, it also has shortcomings, notably the lack of consideration of actual drinking water quality. Processes are underway to shape the global development agenda in the post-MDG era, and improved targets for water and sanitation could be developed, based on the human rights framework. This represents an opportunity to improve upon the ‘improved/unimproved’ indicators. WASH sector professional should advocate for water and sanitation to be well-represented in post-2015 goals and targets. The Joint Monitoring Programme established technical Working Groups which have suggested possible targets and indicators; these would represent a substantial advance in service delivery, but would also require advances in monitoring practices

Measuring use of household drinking water filters: field experiences from Ethiopia

In rural Ethiopia, household defluoridation filters have been distributed in an effort to reduce fluoride exposure through drinking and cooking water. Submersible dataloggers were used to measure stored water levels in household filters, and to calculate the frequency of filter filling, as well as the amount of water added to and withdrawn from filters. These quantitative estimates of filter use are compared against different measures of self-reported filter use. Tally counters were also investigated as an alternative to simple self-reported filter usage. Comparison to datalogger records shows that tally counters underreport the frequency of filter filling, while household reports of filling frequency matched rather closely. However, households report treating much larger volumes of water than were calculated from datalogger records. Datalogger records indicate consumption of approximately 12.5 litres per day per filter, or 2.0 litres per person per day, which is probably adequate for drinking but not for cooking

A History of Pediatric Immunology

Immunology has played a prominent role in the history of medicine. Pediatric immunologists have focused on immune aberrations in pediatric disorders, particularly those involving host defense mechanisms. These efforts have paid rich dividends in terms of fundamental knowledge of the immune system and major therapeutic advances, including 1) i.v. immunoglobulin therapy, 2) hematopoietic stem cell transplantation, and 3) gene therapy. Pediatric immunology as an organized discipline emerged in the early 1950s, when pediatricians and their basic scientist colleagues began to focus on clinical and basic research related to immunodeficiency. Since then, key organizations and infrastructure have been developed to support this research and the clinical care of immunodeficient patients. We review here the evolution of contemporary pediatric immunology, particularly in North America, from its roots in 19th-century Europe to its current expression as one of the fundamental scientific and clinical disciplines of pediatrics. Immunology touches every pediatric subspecialty. Most closely aligned to allergy and rheumatology, immunology also has close ties to infectious diseases, hematology, and nephrology. Furthermore, each other specialty has its autoimmune diseases, relies on immunologic tests for diagnosis, and uses immunosuppressive drugs or i.v. immunoglobulin (IVIG) treatment; yet there are only a handful of patients, those with a primary immunodeficiency, to whom no other specialist lays claim. Because these patients are fairly rare, a practicing pediatrician who devoted his practice to primary immunodeficiency would probably starve. Furthermore, no separate board for pediatric immunology exists, although the American Board of Allergy and Immunology, while emphasizing allergy, now has considerable emphasis on clinical immunology and immunodeficiency. This article details the scientific advances as well as the individuals and the organizations involved in the development of the specialty of pediatric immunology. FOUNDATIONS OF PEDIATRIC IMMUNOLOGY Variolation and vaccination. Conventional wisdom traces the birth of immunology to 1798, when Edward Jenner (1749 -1823) of Gloucestershire, UK, inoculated (vaccinated) material from the cowpox sores of milkmaid Sarah Nelmes into the arms of several teenage boys. One boy, James Phipps, was subsequently exposed to smallpox and found to be fully protected (1). A less well-known event, termed the "Royal Experiment," preceded Jenner's work by several decades. During the smallpox epidemic of 1721, Caroline, Princess of Wales (daughter of King George I), was understandably concerned that her 3-y-old daughter Mary would become infected. She had heard the rumors from China and Turkey and reports by Cotton Mather of Boston and Lady Mary Worthley Montagu, wife of the British Ambassador to Constantinople, that suggested that cutaneous inoculation of a small amount of material from a smallpox lesion (i.e., variolation) would protect against smallpox. Princess Caroline ordered safety and efficacy tests on six prisoners and five orphan children (including smallpox challenge of the inoculated prisoners). Only then did she allow Dr. Charles Mailtand to inoculate Mary (2). 19th-century immunology. A detailed history of immunology has been published (3), and only a summary is provided here. Rudolf Virchow's 1859 treatise on cellular pathology provided the first formal theory for the cellular basis for disease as opposed to disturbances of the humors (blood, phlegm, black bile, and yellow bile) that had reigned for 2000 y. In th

Gaseous Environment Considerations and Evaluation Programs Leading to Spacecraft Atmosphere Selection

The NASA Manned Spacecraft Center has been actively involved in the direction and support of programs leading to the selection and validations of the atmosphere for forthcoming Gemini and Apollo missions. This paper discusses the engineering and physiologic considerations involved, describes the investigations to validate spacecraft atmospheres, and discusses the implications derived from the results of these investigations

Household Pasteurization of Drinking-water: The Chulli Water-treatment System

A simple flow-through system has been developed which makes use of wasted heat generated in traditional clay ovens (chullis) to pasteurize surface water. A hollow aluminium coil is built into the clay chulli, and water is passed through the coil during normal cooking events. By adjusting the flow rate, effluent temperature can be maintained at approximately 70\ub0C. Laboratory testing, along with over 400 field tests on chulli systems deployed in six pilot villages, showed that the treatment completely inactivated thermotolerant coliforms. The chulli system produces up to 90 litres per day of treated water at the household level, without any additional time or fuel requirement. The technology has been developed to provide a safe alternative source of drinking-water in arsenic-contaminated areas, but can also have wide application wherever people consume microbiologically-contaminated water

Arsenic in tube well water in Bangladesh: health and economic impacts and implications for arsenic mitigation

A national drinking water quality survey conducted in 2009 furnished data that were used to make an updated estimate of chronic arsenic exposure in Bangladesh. About 20 million and 45 million people were found to be exposed to concentrations above the national standard of 50 μg/L and the World Health Organization’s guideline value of 10 μg/L, respectively. From the updated exposure data and all-cause mortality hazard ratios based on local epidemiological studies, it was estimated that arsenic exposures to concentrations > 50 μg/L and 10–50 μg/L account for an annual 24 000 and perhaps as many as 19 000 adult deaths in the country, respectively. Exposure varies widely in the 64 districts; among adults, arsenic-related deaths account for 0–15% of all deaths. An arsenic-related mortality rate of 1 in every 18 adult deaths could represent an economic burden of 13 billion United States dollars (US$) in lost productivity alone over the next 20 years. Arsenic mitigation should follow a two-tiered approach: (i) prioritizing provision of safe water to an estimated 5 million people exposed to > 200 μg/L arsenic, and (ii) building local arsenic testing capacity. The effectiveness of such an approach was demonstrated during the United Nations Children’s Fund 2006–2011 country programme, which provided safe water to arsenic-contaminated areas at a cost of US$ 11 per capita. National scale-up of such an approach would cost a few hundred million US dollars but would improve the health and productivity of the population, especially in future generations

Gravity-driven membrane disinfection for household drinking water treatment

Ultrafiltration (UF) has been proven to be very effective in the treatment of water for the removal of particles, colloids and microorganisms. However, household application of UF is limited due to membrane fouling which results in complex and maintenance-intensive UF systems

Microbiological Contamination of Drinking Water Associated with Subsequent Child Diarrhea.

We used a prospective, longitudinal cohort enrolled as part of a program evaluation to assess the relationship between drinking water microbiological quality and child diarrhea. We included 50 villages across rural Bangladesh. Within each village field-workers enrolled a systematic random sample of 10 households with a child under the age of 3 years. Community monitors visited households monthly and recorded whether children under the age of 5 years had diarrhea in the preceding 2 days. Every 3 months, a research assistant visited the household and requested a water sample from the source or container used to provide drinking water to the child. Laboratory technicians measured the concentration of Escherichia coli in the water samples using membrane filtration. Of drinking water samples, 59% (2,273/3,833) were contaminated with E. coli. Of 12,192 monthly follow-up visits over 2 years, mothers reported that their child had diarrhea in the preceding 2 days in 1,156 (9.5%) visits. In a multivariable general linear model, the log10 of E. coli contamination of the preceding drinking water sample was associated with an increased prevalence of child diarrhea (prevalence ratio = 1.14, 95% CI = 1.05, 1.23). These data provide further evidence of the health benefits of improved microbiological quality of drinking water