Kenyan teens win Africa Earth Prize for low‑cost vehicle exhaust filter
Two 17‑year‑old students from Kiambu County, Kenya, were announced as the winners of the Africa regional Earth Prize on May 12 for inventing HewaSafi, a low‑cost exhaust filtration system made from maize husks and coconut fibers. The award, presented by the United Nations‑affiliated Earth Prize, recognizes innovations that address pressing environmental challenges in developing regions.
Air‑quality problems have surged across sub‑Saharan Africa as rapid urbanisation and aging vehicle fleets increase exposure to harmful pollutants. In Nairobi, respiratory illnesses linked to vehicle emissions have risen by 23 % over the past decade, prompting schools and NGOs to seek affordable mitigation technologies.
Mongabay detailed that the students—Frederick Njoroge Kariuki and Miron Onsarigo of the M‑PESA Foundation Academy—engineered a filter that captures up to 85 % of particulate matter (PM2.5) while costing less than $2 per unit. “We wanted something our community could actually afford,” Onsarigo told reporters. The pair cited personal experiences with family members suffering from asthma, which drove the project’s development. The Earth Prize jury, chaired by former UN Environment Programme Executive Director Inger Andersen, praised the solution for its scalability and use of locally sourced agricultural waste.
Environmental engineer Dr. Amina Hassan of the Kenyan Ministry of Environment noted that, if adopted widely, HewaSafi could remove an estimated 12 % of the nation’s total vehicular PM emissions, significantly improving air quality in congested districts. However, she cautioned that rigorous field testing is needed to assess durability under varying climatic conditions.
The award includes a $50,000 seed grant, mentorship from the United Nations Development Programme and a pilot‑deployment program in Nairobi’s informal settlements slated for Q4 2026. Stakeholders will monitor the filtration system’s performance during a six‑month trial, after which the Ministry plans to consider integrating the technology into national vehicle inspection standards. The success of HewaSafi could inspire similar grassroots innovations across Africa, offering a cost‑effective pathway to cleaner air.