Comment on “Adoption of Point-of-Use Chlorination for Household Drinking Water Treatment: A Systematic Review”

Daniele Lantagne,1 Roberto Saltori,2 Esther Shaylor,3 Gabrielle String,4,5 Tracy Wise,6 Robert Quick,7 and Monica Ramos8 Feinstein International Center, Friedman School of Nutrition, Tufts University, Boston, Massachusetts, USA United Nations Children’s Fund (UNICEF), New York, New York, USA Supply Division, UNICEF, Copenhagen, Denmark Department of Civil and Environmental Engineering, Lehigh University, Bethlehem, Pennsylvania, USA Department of Community and Population Health, Lehigh University, Bethlehem, Pennsylvania, USA Office of Technical and Program Quality, U.S. Agency for International Development (USAID) Bureau for Humanitarian Assistance, Washington, District of Columbia, USA Retired from Centers for Disease Control and Prevention, Atlanta, Georgia, USA Global WASH Cluster, UNICEF, Geneva, Switzerland

https://doi.org/10.1289/EHP13164Refers to https://doi.org/10.1289/EHP10839 The systematic review of chlorine-based household water treatment (HWT) adoption by Crider et al. 1 concludes in alignment with the 2015 Sustainable Development Goal 6, 2 which prioritizes delivery of centralized safely managed water and considers HWT insufficient to reach public health goals.
We agree with Crider et al.'s conclusion that ". . .individual adoption for effective treatment is unlikely to lead to the widespread public health benefits historically associated with pressurized, centralized treatment." 1 However, because the authors presented a review of chlorine-based HWT development-context controlled trials, not real-world adoption, we argue that their results should not inform HWT policy, particularly in humanitarian responses.
In their review, Crider et al. analyzed 44 development-context studies (including 42 controlled trials) and two humanitarian emergency studies (one a stable-setting trial 3 and one that violates their "damaged water infrastructure" exclusion criterion 4 ).
Crider et al. did not discuss five systematic reviews, and evaluations, including HWT adoption in humanitarian emergencies, [5][6][7][8][9][10] and misidentified a prototype handheld electrochlorinator as liquid chlorine. 11The authors also used exclusion criteria that were not in their protocol (https://osf.io/f972y),including "large-scale programs," "humanitarian relief efforts . . . in the aftermath of disasters that damaged water infrastructure," and HWT distributed via "social marketing campaigns" (when public health goods are promoted via commercial markets).This last criterion excluded >30 key adoption papers written by one review coauthor.
Crider et al. conclude, without supporting evidence from their review, that ". . .tablet products may be more effective in achieving high levels of use . .." in ". . .humanitarian, emergency, or outbreak situations . .[14][15] Current evidence-based humanitarian HWT programming connects emergency-affected populations to products known before emergency onset, uses HWT as a last resort, and understands logistics, training needs, and government approval. 15Examples of this include: • In Syria in 2014-2016, monitoring data were analyzed to develop a multilevel response strategy. 16,17This strategy included first supporting chlorination in infrastructure, then providing chlorinating trucked water, and then distributing chlorine tablets last.In areas implementing this multilevel strategy, free chlorine residual increased from 21% (baseline) to 61%-90%. 17• In Haiti, after the 2010 earthquake, preexisting locally manufactured, government-approved liquid chlorine products were used for humanitarian response. 18Free chlorine residual in HWT-targeted households without infrastructure was 89.5%, 13 falling to 73% 10 months later, after cholera onset, 14 and 52% in 2014. 19Similarly, in Mozambique, a local governmentapproved liquid product was used during recent cyclone and cholera responses. 20,21umanitarian emergencies, including natural disasters, outbreaks, and conflicts, are increasing in intensity and impact. 6,7To reach populations affected by humanitarian emergencies, outdated recommendations based on development-context controlled trials should not be used.6][7][8][9] Evidence from humanitarian emergencies shows risk is best controlled with multilevel interventions: first, safely managed water; then, local water markets; then, as a last resort, use of locally available chlorine-based HWT products or imported tablets.This strategy aligns with SDG6, 2 the human right to water, 22 and the localization agenda 23 of humanitarian response.
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Letter to the Editor