LAHORE: Dense fog on Friday continued to persist over the plains of Punjab, with Lahore covered in a blanket of smog that made a large number of people, including children, wear masks to fight against the phenomenon caused by the combination of high level of pollutants in the air and calm wind.

The driver of a truck died when it rammed into another at the National Highway’s portion of Renala Khurd on Friday morning because of poor visibility caused by dense fog, according to officials of the Motorway and National Highway Authority.

Smog eased in Lahore to some extent during Thursday night and in the morning hours on Friday. But it again blanketed the city in the early afternoon in the presence of totally calm wind and increasing temperature, creating typical green house effect.

The impact on people was immense despite the fact that many were seen wearing masks to protect themselves against it. Breathing appeared somewhat heavy and though lessened there was eye, nose and throat irritation.

The Environment Protection Department (EPD) said though slowly sliding down, the level of pollution generated by mainly three sources was much beyond the human tolerance level. These included the incursion of carbon monoxide from India which was produced after the burning of nearly 32 tonnes of crop residue by its farmers, gases from the drains and waste material from hundreds of factories in northern and northeast Lahore.

According to fresh readings obtained through the recently installed monitoring equipment, the level of carbon monoxide was 21.29 (milligram per metre) on The Mall, 17.52 in Mohlanwal, and 6.94 in Gulberg’s Liberty Market as against the maximum permissible limit of 5.

The same pollutant is also caused by vehicular traffic but its contribution in the present instance is not dangerous.

The second pollutant is hydrogen sulphide which emanates from drains. Its level on Zafar Ali Road was 772.69 because of its open drain as against the permissible limit of 7 per minute and 150 per 24 hours.

The level of sulphur dioxide that is the product of junk fuel was 1373.1 at Daroghawala, north and northeast Lahore, which houses hundreds of mills, including 600 steel factories. The tolerant upper limit is 120.

Met Department’s Lahore Chief Riaz Khan said pollution from India penetrated Pakistan, especially Lahore, when the wind direction was “towards us in October”. Now wind was calm.

And pollution would be pushed back only after strong north-westerly wind which moves towards India.

He said pollution was slowly easing but only rain could wash it away or strong wind could push it away. At present there was none.

He said a weak westerly wave over northern areas would generate rain over upper parts of the country and up to Rawalpindi in the next 24 hours. But it would remain dry over the plains where fog would again develop, especially over Lahore, Gujranwala, Sargodha, Faisalabad and Toba Tek Singh regions during the night. Smog in Lahore and elsewhere would also persist but with varied intensity.

Motorway authorities said its portions from Lahore to Sial Morr and Pindi Bhattian to Faisalabad remained closed Thursday night because of dense fog that reduced visibility to zero, making travelling conditions highly risky.

Visibility on the National Highway around Manga Mandi, Pattoki, Okara, Sahiwal and Khanewal too was zero because of the blanket of thick fog.

Published in Dawn, November 5th, 2016