GRAP 4 in Delhi: Doctor explains how pollution from old vehicles affects health

• School Closures: All schools, except for classes 10 and 12, have been ordered to shift to online classes.
• Vehicle Restrictions: Entry of non-essential diesel-powered medium and heavy vehicles into Delhi has been banned. Construction and demolition activities have also been halted, with certain exceptions.
• Work-from-Home: Offices in the NCR have been advised to implement a 50% work-from-home policy.

These measures, coupled with those already in place under previous stages of GRAP banning BS-IV or older diesel vehicles, aim to curb pollution and improve air quality in the region.

Air pollution continues to pose serious health risks, particularly in urban areas. Dr Vikas Mittal, a Pulmonologist at CK Birla Hospital, Delhi, explains how emergency measures like GRAP 4 can alleviate pollution’s harmful effects, while ageing vehicles, especially diesel ones, exacerbate the problem by releasing toxic emissions. Understanding these factors is essential for improving air quality and protecting public health.

According to Dr Mittal, these bans offer the following health benefits:

• Respiratory Relief: By lowering exposure to airborne toxins, GRAP 4 prevents acute respiratory conditions and asthma exacerbations.
• Cardiovascular Protection: Decreased particulate matter helps reduce risks of heart diseases and strokes.
• Focus on Vulnerable Groups: Children, the elderly, and individuals with pre-existing health conditions benefit significantly from the cleaner air.

Traffic passes on a road as the sky is enveloped with smog after Delhi’s air quality turned “severe” due to alarming air pollution, in New Delhi, India, November 18, 2024. (Photo: Reuters)

Health risks from pollution by ageing vehicles

Pollution from old vehicles, particularly diesel-based ones, Dr Mittal said, significantly degrades air quality and endangers public health:

1. Harmful Emissions: Aging vehicles release higher levels of carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter (PM), which are linked to respiratory and cardiovascular diseases.
2. Deep Lung Penetration: Fine particulate matter from exhaust enters deep into the lungs, causing chronic respiratory conditions and even increasing cancer risks.
3. VOCs Exposure: Volatile Organic Compounds (VOCs) from old vehicles harm vulnerable populations, including children and those with existing health issues.

The diesel factor

Older diesel vehicles pose even greater threats due to deteriorating engine components and outdated emission technologies, Dr Mittal said. Key concerns include:

• Increased Nitrogen Oxides and Soot: Diesel engines emit NOx and black carbon (soot), aggravating lung diseases and contributing to climate change.
• Carcinogenic Effects: Diesel exhaust is a recognized carcinogen, raising the risk of lung cancer and heart disease.
• Inefficiency Over Time: Aging diesel engines result in incomplete combustion, worsening emissions.

To improve air quality, adhere to GRAP 4 measures and support policies promoting cleaner vehicles and reduced diesel usage.

DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.