Air Quality in Green Areas

Most people assume that if they live near a green area with lots of trees surrounding them, the problem of air pollution will not impact them. The hundreds of trees will act as a barrier to the pollutants coming in. However, the numbers show a very different story. It has been found that the air quality in green areas that are in or near a polluted part of the country, has poor to even hazardous air quality.

There are two important things you need to undestand, before you lull yourself into the familiar complacency of living in a green area within a city. While trees and the green cover is important to keep pollution in check, but a pocket of green cover is only a part of a larger and complex system that is at work.

First and foremost, the trees make the air above them cooler and the warmer air from more polluted areas moves horizontally towards this cooler air making the area with green trees also heavily polluted. Secondly, the Air quality is not a local issue that can be pinned down to a small area. Air is constantly transient, and the air pollution zone of Northern India starts in Pakistan and ends in Bangladesh. Hence a small green zone will not have “clean and healthy” air when everything around is bad and this air is moving constantly. So now that we know that the air can be poor, what are some of the specific pollutants that we get exposed to, and what can we do to reduce our exposure:

• PM2.5 refers to particles with a diameter between 0 to 2.5μm (though what is measured is typically only between 0.3 and 2.5μm) . These are usually called fine particles and can be secondary aerosols, combustion particles and re-condensed organic metallic vapor, and acid components. Fine particles can reach all the way down to the alveoli in the lungs. • PM0.1 refers to particles with a diameter of less than 0.1 μm and are called ultra-fine particles. Ultra-fine particles are the most harmful to our health as they can penetrate into the bloodstream. • The safe levels for PM2.5 exposure is 10μg/m3 for annual average exposure. The average exposure when living in Delhi is 153μg/m3 – about 15 times the safe levels. • To avoid exposure to pollutants, stay indoors as much as possible, seal all windows and openings so that polluted air cannot enter, use an air purifier that is equipped with a True HyperHEPA filter which can effectively remove fine particles from the air. • If you spend more time on the road get high-efficiency HyperHEPA car air purifier which protects against PM2.5, ultrafine particles, allergens, diesel soot, and microscopic particles.

• The main source of Carbon Dioxide (CO2 ) indoors is human beings. At levels over 800ppm, it reduces human productivity significantly, impacts cognitive ability as well as causes discomforts like drowsiness and headaches. • Carbon dioxide cannot be filtered from the air with active carbon or other molecular filters like other indoor gases. Therefore, it needs to be diluted by bringing low CO2 concentration outdoor air into the building (air purifier which has the capability to bring fresh air from outside) or have lots of plants in the space as they remove carbon dioxide.

• VOCs (Volatile organic compounds) are carcinogenic gases that are emitted into the air from certain solids or liquids. It is present in our daily lives. We are constantly exposed to smells from several sources. Formaldehyde, one of the most common VOCs, is a colorless gas with an acrid (sharp and bitter) smell. It is common in many building materials such as plywood, particleboard, and glues.
• Other sources of VOCs include the burning of fuels such as gas, wood and kerosene and tobacco products. VOCs can also come from personal care products such as perfume and hair spray, cleaning agents, dry cleaning liquid, paints, lacquers, varnishes, printing machines, mosquito repellant, deodorant, etc.. VOCs include a variety of chemicals that can cause eye, nose and throat irritation, shortness of breath, headaches, fatigue, nausea, dizziness and even cancer.
• One can get a high quality filter that is capable of removing VOC’s from the air. Typically a simple carbon filter will NOT do this well. One must invest in a higher grade filter that has broad spectrum gas removal capability.

• The gaseous air pollution can be either outdoor or indoor air-based. Outdoor air can contain high concentrations of Carbon Monoxide (CO), Sulfur Oxides (SOx), Nitrogen Oxide (NOx), Ozone (O3 ), Hydrogen Sulfide (H2 S), Ammonia (NH4 ), Dioxins, Furans, and volatile organic compounds (VOC). Most of these gases are related to vehicle emissions, landfills, burning of waste (including plastics) and open sewage systems.
• These gases with high concentrations can create various health effects, like increased respiratory symptoms in people with asthma. Sometimes the combination of particulate matter with gases like NOx are harmful as particulates carrying NOx penetrate deep into the lungs and can cause respiratory disease. Ozone is a lung irritant and high concentration levels of ozone is harmful to our health.
• Again, it is very important that one gets proper analysis and testing done in a living space for these harmful gases. Specially if there are strong odors, electronics tend to fail often, AC pipes get corroded quickly, etc. To protect oneself from damage from these gases, one must invest in high quality gas phase filtration that has the ability to target these harmful gases. Speak to a consultant who knows what they are doing before buying something like this. As we have seen above it is imperative that we work towards clean air for ourselves. We drink 2-4 litres of water and are very particular about the quality of the same. But we breathe 11-13 thousand litres of air each day. What do we do about this?