Problems
Causes of air pollution in Karachi.
Air pollution in Karachi contains solid and liquid particles, and certain gases in the air. The major polluters are transport and industrial emissions followed by burning of garbage, emissions from refrigerators, generators, flying of dust, and stoves used in houses and hotels. Karachi’s present mangroves forest cover is 50,000 hectares. In the last 50 years, Karachi has lost 10,000 hectares of mangrove forest due to encroachments, commercialization, and infrastructure development. A Sindh Environmental Protection Agency report says that the important ecosystems in Sindh, such as mangroves, have come under extreme pressure due to seawater encroachment and deforestation. There has been a mass depletion of mangrove forests in the area due to illegal logging, irrigation, and untreated industrial waste. According to international standards, a country should have at least 25 percent of its total land under forest cover to tackle environmental degradation including air pollution.
Health effects of air pollution in Karachi.
Levels of daily particulates (PM2.5) were monitored at two sites in Karachi, Pakistan. One site (Korangi) is an industrial and residential neighborhood, while the other (Tibet Center) is a commercial and residential area near a major highway. Monitoring was done daily for six weeks during spring, summer, fall and winter. Particulate levels were extraordinarily high, with the great majority of days falling into the “unhealthy for sensitive groups” or “very unhealthy” categories. The mean PM2.5 levels in Karachi exceeded the WHO’s 24 h air quality guideline almost every day and often by a factor of greater than 5-fold. Daily emergency room (ER) visits and hospital admissions for cardiovascular diseases were obtained by review of medical records at three major tertiary and specialized hospitals. ER and hospitalizations were reported relative to days in which the concentration of PM2.5 was less than 50mg/m3, and by 50 mg/m3 increments up to 300mg/m3. There were statistically significant elevations in rates of hospital admissions at each of the PM2.5 categories at the Korangi site, and at concentrations of .150mg/m3 at the Tibet Center site. ER, visits were significantly elevated only at PM2.5 concentrations of between 151 and 200 mg/m3 at both sites. These results show that the extremely elevated concentrations of PM2.5 in Karachi, Pakistan are, as expected, associated with significantly elevated rates of hospital admission, and to a lesser extent, ER visits for cardiovascular disease.
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Timelines
2023
September 27
The metropolitan city of Karachi made a shocking distinction by becoming the most polluted city in the world for two successive days, in terms of air quality, followed by New Delhi, on the Air Quality Index (AQI), according to the Swiss company IQAir that monitors air quality. The concentration of PM2.5 (particulate matter) in Karachi exceeded the WHO’s annual air quality guideline value by a staggering 20.3 times. The concentration of pollutants in Karachi was recorded at 175 AQI. It’s worth noting that an AQI reading in the range of 151-200 is considered unhealthy, while an AQI reading between 201 and 300 is even more detrimental to health. Over the past few years, according to the yearly report issued by IQAir, it is evident that pollution levels in Karachi have not improved but have, worsened.
January
Karachi was ranked the fourth most polluted city in the world by the Air Quality Index (AQI) and topped the world's worst air quality rankings. A rating above 300 is declared dangerous, the city has come close to the 500 mark. In Karachi, 187 particulate air quality indices were measured. After Lahore, Karachi was labeled dangerous to breathe; after the port city's air quality index was recorded at 494. Karachi has also made the list of the most polluted cities in the world, which makes the air extremely unhealthy for residents. A pollution index in the range of 154 to 200 is considered harmful, and any index recorded above 300 is declared hazardous. According to experts, the air becomes heavier in winter than in summer, causing toxic particles in the atmosphere to sink and pollute the atmosphere. As a result, the area is covered with a layer of polluted particles, including large amounts of carbon and smoke. According to experts, smoke from factories or burning coal, garbage, oil or tires enters the atmosphere, and its effects begin with the onset of winter and persist until the end of the season. The AQI calculation is based on five pollution categories: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. While southwesterly winds blowing off the sea in Karachi can act as a filter for the air, experts say these winds are largely silent during the winter. Winds blowing from the northeast increase the concentration of polluted particles, and a healthy atmosphere in such a situation is prone to precipitation, which washes away polluted particles. Pakistan is ranked 3rd among countries by AQI due to the worst air quality.
2022
Karachi has turned out to be the world's fourth largest polluted city as its air quality index has surged to an unhealthy level of 193. PM2.5 concentration, as per IQAir organisation report, in Karachi has been recorded 11.8 times higher which is above the WHO annual air quality guideline value. The investigation finds that air pollution in Karachi contains solid and liquid particles, and certain gases in the air.
2021
Karachi recorded a rating of PM 163, placing the city on the list of the most polluted cities in the world, according to air pollution data released by the US Air Quality Index. Karachi Air Quality Index is one of the four most polluted cities in the world.
2019
In 2019 Karachi came in with a PM2.5 reading of 40.2 μg/m³, putting it into the ‘unhealthy for sensitive groups bracket’, which requires a PM2.5 reading of anywhere between 35.5 to 55.4 μg/m³ to be classed as such. PM2.5 refers to particulate matter that is 2.5 micrometers or less in diameter, making it 3% the size of a human hair, and as such extremely damaging to human health when respired, hence why it is used as a major component of calculating the air quality as well as pollution levels. Karachi's 2019 reading of 40.2 μg/m³ put it in 231st place out of all the most polluted cities worldwide, as well as being the 9th most polluted city in Pakistan.