# Zona air quality indexes

## 1. Zona air quality index

Zona air quality indexes are proprietary indexes that track the average air quality of a city. Indexes are compiled from air quality stations across a city.

Indexes are typically at a city-level granularity, although they can extended to a district-level or country-level index based on user demand.

## 2. Data Pipeline

1. **Collect:** Zona collects data from multiple trustworthy local air quality stations to ensure reliability and redundancy.&#x20;
2. **Cleanse:** The data is then cleansed for errors (e.g. duplicates or extreme outliers). A moving average is then applied to the index, which reduces spikes induced by outliers and allows for a smooth trading experience.
3. **Verify:** The index is backtested against existing industry-leading air quality indexes, ensuring that the values are correct.
4. **Push:** The index is bridged onchain via an oracle service.
5. **Use:** Zona users trade against this index via the Zona exchange.

## 3. What indexes will Zona support?

During our initial developmental stage, Zona plans to support cities where air quality is a major concern for local residents, such as Delhi, Beijing, and more. We ultimately aim to support as many cities around the globe as we can and welcome your feedback as to which regions we should integrate next.&#x20;
