According to data released by CPCB, Bihar's Katihar recorded the worst level of air pollution on Saturday with an air quality index of 429. The cities with worst AQIs include Bihar's Chhapra (397), Buxar (393), Bihar Sharif (380) and Darbhanga (351). The list also includes Delhi (362), UP's Firozabad (360) and Noida (355) and Haryana's Faridabad (356) and Hisar (355).