Question

Which of the following gases cause pollution when present in the exhaust fumes of vehicles? (a) Water vapours (b) \(\mathrm{CO}_{2}\) (c) \(\mathrm{CO}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{6}\)

Short answer

CO is a pollutant in vehicle exhaust fumes.

Step-by-step solution

Identifying Pollutants

First, we need to identify which gases among the options are considered pollutants. Common pollutants in vehicle exhaust include carbon monoxide (CO), nitrogen oxides (not listed here), hydrocarbons, and particulate matter. These substances are typically harmful to humans and the environment.

Environmental Impacts

Water vapors (option a) are not considered pollutants as they are not harmful to health or the environment in the quantities typically produced by vehicles. Compare this to CO and C2H6, which can have significant negative impacts on health.

Identifying Harmful Gases

Carbon monoxide (\(\mathrm{CO}\)) is a colorless, odorless gas that is very harmful as it can interfere with the body's ability to carry oxygen when inhaled. This makes it a pollutant. Ethane (\(\mathrm{C}_{2} \mathrm{H}_{6}\)) is a hydrocarbon, which contributes to air pollution, although it is not as prevalent as other hydrocarbons in vehicle emissions.

Assessing CO2

Carbon dioxide (\(\mathrm{CO}_{2}\)) is a greenhouse gas and is not a pollutant in the traditional toxicological sense, as it is not directly harmful to human health in the doses typically found in the atmosphere. However, it contributes to global warming and climate change.

Conclusion

Based on the understanding of pollutants, carbon monoxide (\(\mathrm{CO}\)) is the primary pollutant among the listed options due to its direct harmful impact on human health.

Key concepts

Air Pollution

Air pollution refers to the presence of harmful or excessive quantities of substances in the air. These substances, known as pollutants, can harm human health and the environment. Pollution can originate from various sources, but one major contributor is vehicle emissions. The transport sector emits various pollutants, which are then released into the atmosphere.

When discussing air pollution, it's essential to consider its effects:

• Health impacts: Pollutants like carbon monoxide and particulate matter from vehicle emissions can lead to respiratory and cardiovascular diseases.
• Environmental effects: Air pollution can lead to acid rain, harming trees and bodies of water.
• Climate change: Greenhouse gases like \(\mathrm{CO}_{2}\) contribute to global warming.

Understanding and mitigating air pollution is crucial for protecting human health and preserving the environment.

Vehicle Emissions

Vehicle emissions are a significant source of air pollution. They consist of gases and particles released into the air as a result of fuel combustion in vehicle engines. The composition of vehicle emissions primarily depends on the type of fuel used, engine efficiency, and vehicle maintenance.

Key components of vehicle emissions include:

• Carbon monoxide (CO): A harmful gas produced due to incomplete combustion of fuel.
• Nitrogen oxides (NOx): Contributing factors to smog and acid rain.
• Hydrocarbons: These include a range of compounds like ethane (\(\mathrm{C}_{2} \mathrm{H}_{6}\)), which can lead to the formation of ground-level ozone, a harmful air pollutant.
• Particulate matter: Tiny particles that can penetrate deep into the lungs and cause various health problems.

Efforts to reduce vehicle emissions focus on improving fuel quality, advancing engine technology, and encouraging the use of electric vehicles.

Carbon Monoxide

Carbon monoxide (CO) is a colorless and odorless gas that is a common component of vehicle emissions. It's a byproduct of burning fossil fuels, and its presence in the air is mainly attributed to incomplete combustion.

The impact of carbon monoxide exposure is significant:

• Health risks: CO interferes with the body's ability to transport oxygen by binding to hemoglobin in the blood, potentially leading to severe health issues or even death.
• Avoidance: Ensuring proper vehicle maintenance can reduce CO emissions. Additionally, promoting the use of cleaner fuel alternatives and advanced engine technologies can minimize exposure.

Addressing the problem of carbon monoxide requires comprehensive measures, including stricter emission standards, routine vehicle checks, and public awareness initiatives.