(P23-004-25) Rural Heat Islands in South Asian Food Markets in Relation to Food Availability, Price Uncertainty, Price Rises, and Spoilage

Objectives: Climate change affects food security through availability, affordability, and safety. Most South Asians rely on outdoor food markets where dense infrastructure, limited green space, and customer congregation may precipitate heat island effects, with markets warmer than nearby areas. We quantify heat islands in rural outdoor food markets and assess associations with food scarcity and spoilage and price uncertainty and rises.

Methods: Shop vendors randomly sampled within five districts—Rajshahi and Rangpur in Bangladesh, Nalanda in India, and Banke and Surkhet in Nepal—reported scarcity, price uncertainty, price rises, spoilage, and shop characteristics from February to June 2023. Infrastructure and food quality were observed. Landsat 9 thermal bands calculated land surface temperature (LST) nearest to survey dates. Heat island intensity was the difference between vendor and district mean LST. Hotspots were ≥2 SD above district mean LST. Logistic regressions assessed associations of heat island intensity with scarcity, price uncertainty, price rises, and spoilage, adjusted for vendor type, harvest season, district clusters, and sample weights, with LST and hotspot proximity sensitivity analyses.

Results: Of 3,808 vendors, 70% used semi-permanent structures and ≥30% sold refined grains, processed foods, or pulses. Spoilage and price uncertainty were highest during harvest season. Heat island intensity (+2.6°C) was associated with lower fruit scarcity (OR: 0.90 [95% CI: 0.82,0.99]) and 4-14% higher odds of scarcity for roots, pulses, eggs, milk, and refined grains. Hotspot proximity—9% of vendors in hotspots, 24% within 500m—had inverse associations. Price uncertainty and price rises were associated with hotspot proximity for vegetables, eggs, and fish but not heat island intensity or LST. Heat island intensity and LST were associated with 5-10% lower odds of spoilage for fruits, leafy vegetables, and refined grains, while hotspot proximity was associated with higher spoilage for fruits (1.16 [1.03,1.30]) and pulses (1.94 [1.78,2.12]).

Conclusions: Heat islands in rural food markets may exacerbate seasonal food insecurity. Remote sensing can help monitor heat islands and direct climate-smart strategies to improve access to sustainable healthy diets.

Funding Sources: Transforming Agrifood Systems in South Asia through the CGIAR Trust Fund