However, with the exception of sulfur dioxide, the amounts of these pollutants in the air have continued to increase over the past six years — with the growth of lead and nitrogen dioxide being particularly exponential.
The level of lead, notorious for causing brain and nervous system damage when congested in large amounts, stood at 0.33 microgram per cubic nanometer (mcg/nm3) last year; over 10 times higher than the level in 2008, and one-sixth of the hazardous threshold of 2 mcg/nm3.
The amount of nitrogen dioxide, meanwhile, rose to 74.14 mcg/nm3 last year — three times its 2008 figure and is alarmingly coming closer to the dangerous threshold of 92.5 mcg/nm3. Nitrogen dioxide is known to be poisonous to lungs.