US research says nitrogen dioxide in restaurants that cook with gas can exceed WHO limits, which also affects diners Each time we enjoy a meal out or order a takeaway, someone cooks for us in a commercial kitchen. In the UK, 3. 6 million people work in catering and hospitality.
Source: [Guardian International](https://www.theguardian.com/environment/2026/oct/16/commercial-kitchen-staff-exposed-high-levels-air-pollution)