Heavy metal contamination in urban agriculture: Evidence from Nairobi
Agricultural production in urban areas plays an important role in food systems in low- and middle-income countries but also may also be subject to significant environmental hazards. We analyze samples of leafy greens grown on farms in Nairobi County selected via random geographical sampling for thre...
| Autores principales: | , , , |
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| Formato: | Journal Article |
| Lenguaje: | Inglés |
| Publicado: |
Springer
2025
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| Materias: | |
| Acceso en línea: | https://hdl.handle.net/10568/177940 |
| _version_ | 1855525951521161216 |
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| author | Murphy, Mike Wachira, Githenya Onyango, Cecilia Hoffmann, Vivian |
| author_browse | Hoffmann, Vivian Murphy, Mike Onyango, Cecilia Wachira, Githenya |
| author_facet | Murphy, Mike Wachira, Githenya Onyango, Cecilia Hoffmann, Vivian |
| author_sort | Murphy, Mike |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Agricultural production in urban areas plays an important role in food systems in low- and middle-income countries but also may also be subject to significant environmental hazards. We analyze samples of leafy greens grown on farms in Nairobi County selected via random geographical sampling for three heavy metals harmful to human health (lead, cadmium, and mercury). The mean levels of contamination are 0.68 ppm for lead, 0.09 ppm for cadmium, and 0.11 ppm for mercury. Spatial analysis shows that crops grown closer to roadways have higher levels of lead contamination and those grown near industrial sites have higher levels of mercury. We disaggregate our sample and test native greens and kale sourced from outside Nairobi as potential substitutes for urban-grown kale but find similar contamination levels. We estimate that 71% of adults and 69% of children in our sample are exposed to lead in excess of daily reference levels, with 12% of adults exceeding levels for cadmium and 52% exceeding levels for mercury via leafy greens alone. Using representative data for Nairobi and results from sampling leafy greens from local wholesale markets, we estimate similar dietary exposure levels for the population of the city as a whole. Our findings demonstrate the importance of systematic surveillance of foods in LMICs for heavy metals and the need to identify and mitigate sources of contamination. |
| format | Journal Article |
| id | CGSpace177940 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Springer |
| publisherStr | Springer |
| record_format | dspace |
| spelling | CGSpace1779402025-12-15T20:17:20Z Heavy metal contamination in urban agriculture: Evidence from Nairobi Murphy, Mike Wachira, Githenya Onyango, Cecilia Hoffmann, Vivian heavy metals polluted soils contamination urban agriculture health health hazards Agricultural production in urban areas plays an important role in food systems in low- and middle-income countries but also may also be subject to significant environmental hazards. We analyze samples of leafy greens grown on farms in Nairobi County selected via random geographical sampling for three heavy metals harmful to human health (lead, cadmium, and mercury). The mean levels of contamination are 0.68 ppm for lead, 0.09 ppm for cadmium, and 0.11 ppm for mercury. Spatial analysis shows that crops grown closer to roadways have higher levels of lead contamination and those grown near industrial sites have higher levels of mercury. We disaggregate our sample and test native greens and kale sourced from outside Nairobi as potential substitutes for urban-grown kale but find similar contamination levels. We estimate that 71% of adults and 69% of children in our sample are exposed to lead in excess of daily reference levels, with 12% of adults exceeding levels for cadmium and 52% exceeding levels for mercury via leafy greens alone. Using representative data for Nairobi and results from sampling leafy greens from local wholesale markets, we estimate similar dietary exposure levels for the population of the city as a whole. Our findings demonstrate the importance of systematic surveillance of foods in LMICs for heavy metals and the need to identify and mitigate sources of contamination. 2025-09 2025-11-14T21:23:09Z 2025-11-14T21:23:09Z Journal Article https://hdl.handle.net/10568/177940 en Open Access Springer Murphy, Mike; Wachira, Githenya; Onyango, Cecilia; and Hoffmann, Vivian. 2025. Heavy metal contamination in urban agriculture: Evidence from Nairobi. Environmental Science and Pollution Research 32(44): 25231-25245. https://doi.org/10.1007/s11356-025-37030-x |
| spellingShingle | heavy metals polluted soils contamination urban agriculture health health hazards Murphy, Mike Wachira, Githenya Onyango, Cecilia Hoffmann, Vivian Heavy metal contamination in urban agriculture: Evidence from Nairobi |
| title | Heavy metal contamination in urban agriculture: Evidence from Nairobi |
| title_full | Heavy metal contamination in urban agriculture: Evidence from Nairobi |
| title_fullStr | Heavy metal contamination in urban agriculture: Evidence from Nairobi |
| title_full_unstemmed | Heavy metal contamination in urban agriculture: Evidence from Nairobi |
| title_short | Heavy metal contamination in urban agriculture: Evidence from Nairobi |
| title_sort | heavy metal contamination in urban agriculture evidence from nairobi |
| topic | heavy metals polluted soils contamination urban agriculture health health hazards |
| url | https://hdl.handle.net/10568/177940 |
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