Delhi was this week blanketed with toxic fog after hundreds of thousands of people set off fireworks to mark Diwali (Report, 1 November). The pollution levels were up to 42 times the safe limit and even exceeded the normal harmful air in the city from traffic. In Britain, firework night and the following day are the peak days for hospital admissions for asthma and other breathing problems. Fireworks pollute the air with toxic heavy metals such as lead, mercury, aluminium, cadmium and radioactive barium, etc. Some of these are used to give fireworks their colours. Smoke from fireworks consists of fine toxic dusts that can enter the lungs. Work should be done to produce fireworks that are less harmful to health and the environment.

Ann Wills

Ruislip, Middlesex

• A couple of days before bonfire night and I’ve just picked a small but choice bowl of raspberries and eaten them outside in pleasant sunshine. November used to be all baked potatoes and roast chestnuts.

John Bailey

St Albans

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