Heat, dust raise toxin levels in Delhi air

Day temperatures retreated marginally on Thursday but there was little relief from the oppressive heat even as toxins in the air increased alarmingly due to a cloud cover trapping pollutants. The capital's air quality index (AQI) broke through the 'severe' level, going from 219 (poor) on Wednesday to 410 in one of the sharpest single-day increases in recent months.

Fine particle pollution (PM2.5) was not the only threat lurking in the capital's air. The past week saw torrid weather make headlines, and levels of the highly toxic ozone (O3) gas also stood high, often double the safe standard of 50 parts per billion.

While PM2.5 comprises minute particles capable of making deep ingress into a person's lungs, exposure to O3 trigger respiratory distress. It could aggravate lung diseases including asthma and chronic bronchitis and also inflame the airways.

Some people may have their lungs permanently damaged depending on the exposure.

According to Dr Sandeep Salvi, head of the Chest Research Foundation, Pune, together, ozone and PM2.5 could play havoc with people's health and those exposed to the pollutants, even for a short duration could suffer respiratory problems, Times of India reported.

He added, together, ozone and PM2.5 could play havoc with people's health and those exposed to the pollutants, even for a short duration, could suffer respiratory problems. He said asthma and chronic obstructive pulmonary disease (COPD) patients were at high risk.

Meanwhile, according to the Indian Meteorological Department (IMD), toxic ozone levels had breached the permissible limit in Delhi.

Over the last two weeks, the level of toxic ozone in the national capital reached its peak when the temperature hovered above 40 degrees Celsius.

On Wednesday, the capital's air quality index (AQI) breached the 'severe' level, going from 219 (poor) to 410 in one of the sharpest single-day rises in recent months.

Meanwhile, according to experts, ultraviolet levels in Delhi were also way above safe standards.

According to scientists, the dust storm early Thursday morning led to both PM10 (coarse pollution particles) as also PM2.5 levels to peak dramatically.

Scientists also mesured PM2.5 at as high as 250 micrograms per cubic metres, over four times the safe level.

In a recent move, System of Air Quality Weather Forecasting and Research (SAFAR) along with the Indian Meteorological Department (IMD) launched the Ultraviolet (UV) index for Delhi, which provides forecast of the expected risk of overexposure to UV radiation from the sun.

SAFAR also found that the UV index for Delhi on Thursday was 7.2 as against the safe range 1 to 4.