Airborne particles are all around us – they come in many different forms, such as grit, dust, smoke, fume, or mist, and we should not forget smog and fog. The types of dust are numerous: mineral dusts, such as those containing free crystalline silica (e.g. as quartz), coal and cement dusts; metallic dusts, such as lead, cadmium, nickel, and beryllium dusts; other chemical dusts, e.g. many bulk chemicals and pesticides; organic and vegetable dusts, such as flour, wood, cotton and tea dusts, pollens; biohazard dusts, such as viable particles, moulds and spores.
Although we can’t see them, the air we breathe is full of microscopic particles. These particles can be health hazardous and are thus considered as a specific type of air pollution. The size of these particles is in the order of several nanometres to several micrometres. Epidemiological studies have shown beyond doubt an association between increased urban air pollution and adverse health effects on susceptible sectors of the population, particularly the elderly who may have pre-existing respiratory or cardiovascular diseases. Urban air contains particles whose size may be classed as coarse through to ultrafine (<0.1 μm in diameter). Ultrafine particles contribute very little to the total mass in a sample of air, but they exist in very high numbers which in episodic events can reach several hundred thousand/cm3 in the urban air.
Not all dusts arise from human activity – high winds in desert regions and volcanic events are both natural phenomena that cause high airborne dust concentrations. So, weather conditions, the natural environment, and human activities can cause windblown, construction, or fugitive dust which contributes to air pollution. High winds can raise large amounts of dust from areas of dry, loose, or disturbed soil.
An adult person typically breathes 17000 litres of air daily – so a low concentration of airborne contaminant represents a large quantity of the contaminant entering the human body by inhalation. Every day billions of particles are inhaled with the ambient air by every human being. Many of these particles are deposited in the respiratory tract - the deposition depends on the size, density, shape, charge, and surface properties of the particles and the breathing pattern of the individual. From the toxicological point of view, all particles smaller than 10 μm in diameter have the potential of being biologically active in susceptible individuals.
Irritation of the nasal passages by dust and its soiling effects are matters of common observation, and some of the unpleasant manifestations such as hay fever and asthma are experienced by many. The case against dust and air pollution is not confined to their unpleasantness. Silicosis, caused by inhalation of minute particles of silica, and other forms of pneumoconiosis (caused by inhalation of dust including, for example, asbestos, coal, metallic particles, decaying organic matter from vegetation or bird droppings) are serious pulmonary diseases. In short, many airborne particles are the source of disabling or fatal illnesses. There is no need to question the need for air cleaning.
Air filtration is a field that encompasses a vast platform linking modern science and technology, in both our day-to-day and industrial activities. The last 2,000 years of the history of air filtration reflects the path of triumphs and trials we have traversed along empirical endeavours to understand air filter performance. Filtration theories have become increasingly well developed in the past 60 years. This is a testament to the ushering in of high-speed computer applications into the field of air filtration, as they emerged in the 1960s. With the rising tide of air pollution, population growth, industrialization, and urbanization, the demand for clean air is mounting as its access is declining.
Through my twenty-two years of experience in the industry and academia, I have become convinced that the air filtration field is interconnected to several fields in science and technology. Therefore, air filters must be selected appropriately and manufactured professionally in order to conduct textbook filtration. Providing filtered air of various efficiencies can have well-pronounced effects on our well-being, HVAC equipment, gas turbine performance, and many other industrial applications. Ultimately, filtration must be regarded as a main tool and provider for clean air, not just as an accessory.
If we look at the bigger picture, it is hard to bring up air quality without citing air pollution, and it hard to address air pollution without highlighting the role of filtration. It is impossible to deny that the access to clean air is declining, so if clean air is really a human right, then we must secure its delivery to over 7 billion people worldwide, half of whom live on approximately $2 per day. I am certain that tomorrow some children will walk barefoot for two hours to get to school and return home to neither shelter nor access to sanitation. Today, doctors who do not have proper access to adequate health care facilities will operate some patients who seek medical care as they fight illnesses on their own. It may seem naive to demand clean air for such individuals who lack the basic needs to survive. However, I have already taken the initiative to provide them with clean air by seeking knowledge and lighting a candle next to it for others to learn.
I truly believe that if we promise our kids a cleaner climate than the one we have inherited, then our environmental actions must match our promise. If we realize the ethical obligation of appropriate filter selection in realigning HVAC systems to provide cleaner air, then we must remember who could be the end-user could be – an infant struggling to survive, sick children, an open heart or lung cancer patient, or that individual who is one moment away from his/her ultimate fate. If the fact that 300 million children are exposed to an air quality six times higher than the international guidelines is not tough enough to accept, then we should really check out our ethical compass. Quite simply, we have clearly failed to defend these 300 million children.
From the “Seeds” platform, I take a pledge to re-write our understanding of clean air and how sustainable strategies in terms of emission reduction and filtration can contribute to better air quality.
Dr. Iyad Al-Attar