Lahore, Pakistan: On the streets of Pakistan's second biggest city, smog stings eyes and burns throats. Inside homes, few people can afford air purifiers to limit the damage of toxic particles that seep through doors and windows. Lahore - a city of 14 million people stuffed with factories on the border with India - regularly ranks among the world's most polluted cities, but it has hit record levels this month.

Get exclusive content with Gulf News WhatsApp channel Schools have closed in the main cities of Punjab province, of which Lahore is the capital, until November 17 in a bid to lower children's exposure to the pollution, especially during the morning commute when it is often at its highest.Schools have closed in the main cities of Punjab province until November 17 "The children are constantly coughing, they have constant allergies. In schools we saw that most of the children were falling sick," said Rafia Iqbal a 38-year-old primary school teacher in the city that borders India.

Her husband Muhammad Safdar, a 41-year-old advertising professional, said the level of pollution "is making daily living impossible". "We cannot move around, we cannot go outside, we can do nothing at all," he told AFP. According to the international Air Quality Index Scale, an index value of 300 or higher results is "hazardous" to health and Pakistan has regularly tipped over 1,000 on the scale.

In Multan, another city of several million people some 350 kilometres away, the AQI level passed 2,000.