According to sources, after the tender deadline closes next week, the BMC will evaluate the submissions and within a week the contractor would be selected for supplying the vans. Even as the threat of deterioration in air quality looms with a slightly early Diwali this year, the Brihanmumbai Municipal Corporation (BMC) has extended its deadline for selecting a contractor to supply four mobile air quality index (AQI) monitoring vans for Mumbai. While the tender for acquiring these vans was floated in August this year and the deadline was set for September 25, the civic body has now extended the deadline to October 7. A senior BMC official told The Indian Express that so far, BMC has received 15 responses from different contractors. This year, as Diwali falls on October 21, it is anticipated that Mumbai’s air quality will plummet owing to bursting of firecrackers and slowing down of wind patterns as winter sets in.