Development and Implementation of Sustainable Air Ventilation Systems for Rural Nicaragua

Abstract

Research Questions: There are four essential questions: Is it possible to build, install, and maintain an air ventilation system in rural Nicaragua? Will such a system be accepted by and utilized by participant households? Will indoor air quality be improved after installation of the ventilation units? Will the overall health of the families be improved due to improved air quality?

Background, Significance, and rationale: Wood fires are commonly used in the developing world for multiple purposes including heating the home and cooking. Exposure to smoke is particularly high in women and children due to traditional roles of fire preparation and child rearing. Exposure to harmful pollutants produced by wood fires has been linked with negative health impact ranging from respiratory problems to cardiovascular issues, headaches and more. Our goal was to implement a low-cost ventilation system in a small cohort of homes across rural Nicaragua with the goal of improving respiratory health outcomes in the subject population.

Materials and Methods: A solar-powered air ventilation system was design for $60/unit and installed in 12 homes in rural Nicaragua. Due to low initial compliance with the use of the solar-based system, an unpowered hood and chimney system was developed and subsequently installed in the place of the solar units. This unit was installed in 17 households and environmental air quality and health outcomes were assessed. Environmental air quality was assessed using a novel field measurement approach that leveraged filter paper and a free spectroscopy web application (“Albedo”). This provided a low-cost, portable, estimate of relative air quality before and after the application of both interventions (solar-vent, hood-vent). Wellness of participants was measured using a survey and measurement of vitals and exhaled carbon monoxide (ECO). These data were obtained at baseline and after a minimum of 8 months post-installation of the hood unit. A total of 20 individuals (13 females and 7 males) completed both baseline and post-data.

Results: It was possible to install an effective low-cost ventilation system with hood systems being preferable to solar-powered systems due to low acceptance/compliance of the solar vent. The hood systems grossly reduced household air pollution in target households. ECO was significantly improved among both males and females (females P<0.001, males p<0.011). After a minimum of 8 months of hood use, several health parameters significantly improved. Among females (n=13), there was strong evidence for a reduction in coughing (p=0.010), chest tightness (p=0.021), and itchy watery eyes (p=0.030); among males (n=7), there was strong evidence for a reduction in coughing (p=0.023) and vision problems (p=0.023), and moderate evidence for reduced in headaches (p=0.043) and fatigue (p=0.043).

Conclusion: It is possible to build a low-cost ventilation system that effectively reduces indoor air pollution. Hood-type systems achieve effective reduction in pollution while achieving superior use compliance in rural Nicaragua. Health measures associated with ventilation and hood systems demonstrated significant evidence of reduced health complaints and objective measurements of household air pollution (HAP) exposure via ECO and field spectroscopy.