Air Pollution's Impact On Colombia's Environment And People

Air pollution is a pressing issue in Colombia, with a study for the World Bank finding that it kills 15,000 Colombians annually. While outdoor pollution is a concern, particularly in cities, indoor air pollution caused by cooking and heating with wood and other solid fuels is also a major issue, especially in rural communities. Bogota, the capital city, has moderate air pollution levels, with a PM2.5 reading of 13.1 μg/m³ in 2019, mainly due to vehicle emissions and factories. The Colombian government is taking steps to improve air quality, such as deploying electric buses and launching the Biodivercities Alliance for better air quality monitoring.

Vehicular emissions

In Bogota, emissions from heavy-duty vehicles such as trucks, lorries, and buses are a significant contributor to air pollution. These larger vehicles often have outdated engines and run on diesel or lower-quality fuels, producing larger amounts of pollution and novel chemicals. The rapid urbanization and population growth in Colombia have also led to an increase in the number of vehicles on the road, exacerbating the problem.

To address this issue, Bogota has taken steps towards reducing air pollution by deploying electric buses to replace diesel vehicles in its public transit system. This initiative is expected to prevent the release of 16,000 metric tons of carbon dioxide annually. Additionally, Colombia has launched the Biodivercities Alliance for Better Air, a $2.5 million project funded by a national carbon tax, to help identify sources of air pollution and develop nature-based solutions.

The impact of vehicular emissions on air quality is not limited to Colombia's cities. In the tropical valley city of Medellin, trees near areas with high vehicular emissions are affected, acting as a barrier to the emitted pollutants. Some tree species, such as Mangifera Indica, exhibit higher tolerance to these pollutants, while others like Tabebuia chrysantha-rosea, Erythrina fusca, and Spathodea campanulata are more sensitive.

The effects of vehicular pollution on ambient air quality were also studied in Srinagar City, India, where similar issues were observed. The study found that locations with higher traffic density had significantly higher concentrations of pollutants, including PM1, PM2.5, PM4, PM10, total suspended particulates (TSP), and carbon dioxide (CO2). The impact of vehicular emissions was particularly pronounced during the winter season, when lower temperatures and stagnant weather conditions contributed to the accumulation of pollutants in the air.

To summarize, vehicular emissions, especially from heavy-duty vehicles, play a significant role in air pollution in Colombia. Initiatives to reduce emissions, such as transitioning to electric buses and implementing nature-based solutions, are important steps towards improving air quality and protecting the health of Colombia's citizens and ecosystems.

Factory emissions

Black carbon, a product of incomplete fossil fuel combustion, is of particular concern due to its small size and ability to penetrate deep into the lungs, causing respiratory issues. It also absorbs solar radiation, contributing to climate change by increasing temperatures. VOCs, such as benzene and formaldehyde, have serious health effects, especially with prolonged exposure.

Nitrogen dioxide and sulfur dioxide are released primarily by heavy-duty vehicles like trucks, lorries, and buses, which often use outdated engines and lower-quality fuels like diesel. NO2 is a major component of car exhaust and is often used as an indicator of traffic congestion.

The impact of factory emissions on air quality is more pronounced in rapidly urbanising areas, where the exponential growth in vehicle numbers and industrial activity exacerbates pollution levels. Poorly maintained roads and construction sites further contribute to the problem by generating large amounts of finely ground dust.

While Colombia's air quality has shown marginal improvements in recent years, especially in the capital city of Bogota, overall, the country's pollution levels remain a concern. The appropriate steps must be taken to ensure a continued positive trajectory, as air pollution is linked to high mortality rates and respiratory-related health issues.

Construction sites

The movement of machinery and vehicles on construction sites also contributes to air pollution. Many of these vehicles run on diesel fuel, releasing pollutants such as carbon monoxide, carbon dioxide, nitrogen oxides, and hydrocarbons. Diesel-powered equipment is a significant source of greenhouse gas emissions, exacerbating climate change. The burning of fossil fuels, such as diesel, to run machinery also contributes to the production of greenhouse gases.

In addition to the immediate health and environmental impacts, air pollution from construction sites can reduce visibility and even lead to accidents on major roads and intersections.

The impact of construction sites on air quality is not limited to Colombia but is a global issue. Data from the United States shows that construction accounts for 14.5% of particulate matter in the air and 8% of total emissions. Similarly, in London, construction contributes to 30% of particulate matter (PM10) emissions, 8% of fine particulate matter (PM2.5) emissions, and 4% of nitrous oxide emissions.

To mitigate the negative impacts of construction sites on air quality, several measures can be implemented:

• Sustainable practices: This includes designing more sustainable construction projects, using sustainable and pollutant-free building materials, and adopting dust suppression and waste management practices.
• Air quality monitoring: Establishing a high-resolution air quality monitoring network can help construction sites understand their pollution exposure and take necessary steps to reduce negative impacts.
• Regulations and best practices: Implementing and enforcing regulations, such as those outlined by the Toronto Environmental Alliance, can help manage and reduce air pollution from construction sites.
• Low-emission machinery: Using low- and zero-emission construction equipment, such as battery-powered options, can significantly reduce air pollution and greenhouse gas emissions.

Road dust

Colombia's rapid urbanisation and increasing vehicle usage contribute to the problem of road dust. The country's air pollution is mainly caused by vehicular and factory emissions, but road dust is also a contributing factor.

The health risks associated with road dust include respiratory and cardiovascular issues. Studies have shown that cyclists in Bogotá are exposed to high levels of fine particulate matter (PM2.5) and black carbon, with concentrations far exceeding the threshold values established as potentially dangerous for human health.

To mitigate the issue of road dust, efficient management strategies are necessary, especially in industrial areas, to protect the health of employees and residents. Additionally, regular cleaning of roads, especially in areas with high human exposure, is crucial.

Household air pollution

The situation is particularly dire in rural communities, where household air pollution is responsible for 17% of all deaths. This is significantly higher than in metropolitan areas like Bogota, Valle de Aburra, and Cali, where outdoor air pollution is a more prominent issue, causing about one in 20 deaths.

The most dangerous airborne particles, known as PM2.5, are those with a diameter of less than 2.5 thousandths of a millimetre. These particles can penetrate deep into the lungs and have been linked to various health issues. The World Health Organization (WHO) has set a limit for average outdoor ambient air pollution of 10 micrograms of PM2.5 per cubic metre of air. However, in rural Colombian households, the concentration of PM2.5 can be up to 26 times the WHO guideline.

To address this issue, it is recommended to replace open fires and traditional stoves with improved cookstoves that have chimneys. This can reduce exposure to harmful particles by half. However, even with these improved cookstoves, the pollution levels still exceed the recommended limit. For more significant improvements, households need to transition to using propane (LPG), which is a more expensive option. Using gas as the primary fuel is a key reason why urban households have lower pollution levels.

By adopting improved cookstoves, the risk of disease and death could be reduced by 30%. Additionally, transitioning to LPG could further reduce disease and death by 45-65%. While improved cookstoves are relatively expensive, they have been successfully implemented in other countries in the region, such as Mexico, Peru, and Guatemala. These improved cookstoves use less wood, resulting in fuel cost savings.

To make a significant impact on reducing household air pollution in Colombia, it is important to involve entire communities. Converting all households to LPG use could save 4,700 lives annually and reduce disease and death by two-thirds. While this transition comes at a high cost, the benefits in terms of improved health, reduced fuel costs, and time saved would be three times the investment.

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