Air pollution is the presence of harmful materials in the air around us, including particulates, smoke and waste gasses. It causes death and illness in humans, animals and even plants if left unchecked. Air pollution inside homes and outdoors in urban areas are considered the most dangerous examples of pollution, and according to the World Health Organisation, kill at least 7 million people every year worldwide.
What makes up air pollution?
There are many different types of pollutants, but the most important to our health are:
- particulate matter
- carbon monoxide
- sulphur dioxide
- nitrogen oxides
- volatile organic compounds
Particulate matter is most often ash, released during any form of combustion. Larger particulates (10 micrometres or more in diameter) are most often found near roadways and some factories. Smaller particulates (2.5 micrometres or less) often form as secondary pollutants.
Nitrous oxides are predominately emitted from motor vehicles, whilst carbon monoxide forms during combustion.
Sulphur dioxideis formed when burning sulphurous materials such as coal or gas.
Ozone is a secondary pollutant formed as part of a wide variety of chemical reactions catalysed by sunlight.
Almost all of these types of pollution are caused by people. For example, only 1% of sulphur dioxide is naturally occurring at the earth’s surface. The other 99% is from human action. Many of these chemicals are not themselves greenhouse gases – the chemicals that cause global warming – but are often formed in the same processes.
Pollutants can be primary – emitted directly from a source, or secondary.
Secondary pollutants form when primary pollutants interact with the environment, usually water or sunlight. Smog, peroxyacetyl nitrate and ground level ozone are common secondary air pollutants.
Where does pollution come from?
Pollution has many different sources. Some natural sources of pollution include:
- volcanic eruptions
- forest fires
- dust and pollen
While harmful, natural pollution tends to be brief in duration, and are not centered around cities in the way that man-made or artificial pollution is, so is less of a threat. Some harmful gases like carbon monoxide are odorless and colorless and hence we human will not able to see or smell it if they are present around us. But carbon monoxide are very harmful and it is important that we keep this gas under control. There are various carbon monoxide alarm and detector in UK that can detect their presence. The most harmful sources of artificial pollution include:
- furnaces and incinerators
- motor vehicle exhaust, including cars, ships and aircraft
- Solvents and fumes, as from paint, hair spray and chemicals
- Landfill waste gasses, such as methane
As you can see, the sources of man-made pollution tend to be located in and around cities, and emit a fairly constant amount of harmful material into the air. As a result these pollutants form the greatest threat to human health, especially those who are especially vulnerable due to age, illness or pregnancy.
How does the weather affect air ploution?
The day to day air quality of an area depends on many variables. Some of the most important factors in the amount of pollutants we actually breathe depend on the weather.
- Rain can remove sulphur dioxide and coal pollutants from the air, but results in acid rain and polluted water.
- Temperature inversions can trap large amounts of pollutants within the area of a city, preventing them from being blown away into the atmosphere in general.
- Winter smog, what many people associate with London, accumulates when the emissions of factories and vehicles become too dense.
- Photochemical smog, more associated with Beijing and many other Chinese cities, is a form of secondary pollution formed when primary pollutants interact with sunlight. It is composed of ozone, aldehydes, and other chemicals.
Inside air can become polluted as well!
It is important to realise that pollution doesn’t just occur outside. The air in our homes and at work can be 50-80% as polluted as the air outside. As we spend around 90% of our lives indoors, this is the type of pollution that has the greatest impact on our health.
Carbon Monoxide and dangers to our health
Carbon Monoxide or CO, is a toxic gas that you cannot see or smell. The industrial processes where carbon monoxide may be produced include: metal manufacturing, electricity supply, mining metal ore and coal, food manufacturing, extracting oil and gas from land or sea, production of chemicals, cement lime, plaster and concrete manufacturing, and petroleum refining. Diagnosing carbon monoxide poisoning can be difficult as it can simulate many other conditions. The effects depend on how much carbon monoxide is in the air, how long it is breathed, and how healthy, active, and sensitive to CO an individual is. CO is given off whenever fuel or other carbon-based materials are burned.
The locations that continue to have high concentrations of CO tend to have topographical or meteorological characteristics that exacerbate pollution; for example, strong temperature inversions or the existence of nearby hills that inhibit wind flow may limit pollutant dispersion. According to statistics from the Department of Health, the most common indication of CO poisoning is a headache (90% of patients), nausea and vomiting (50%), vertigo (50%), confusion/changes in consciousness (30%), and weakness (20%). The beginning symptoms of CO poisoning are sometimes compared to the symptoms of food poisoning. Exposure to CO is worse for older people, fetuses, and people with heart, circulatory, or lung disease. CO usually comes from sources in or near your home that are not properly maintained or vented. As can be seen from the table, the symptoms vary widely based on exposure level, duration and the general health and age on an individual.
Most people have experienced some of these symptoms at one time or another, which doesn’t necessarily mean that CO poisoning caused them. The highest levels of CO typically occur during the colder months of the year when inversion conditions (when the air pollution becomes trapped near the ground beneath a layer of warm air) are more frequent. If untreated, exposure to carbon monoxide gas can prevent red blood cells from carrying oxygen to body tissue. Also note the one recurrent theme that is most significant in the recognition of carbon monoxide poisoning – headache, dizziness and nausea. Carbon monoxide detectors, which are designed to protect against high concentration of carbon monoxide are required to sound an alarm when concentrations are greater than 100 ppm.
Once carbon monoxide attaches, it is very difficult to release. Long term effects can include brain damage, including problems with memory, mood, behaviour and language. So if you breath in carbon monoxide, it sticks to your hemoglobin and takes up all of the oxygen binding sites. In order to assess whether low level carbon monoxide exposure is, in fact, a problem in the UK, two important factors need to be taken into account: the number of people potentially affected by low levels of CO in their homes, and the severity and likelihood of long term effects. Eventually, your blood loses all of its ability to transport oxygen, and you suffocate.
Why You need carbon monoxide detector
Carbon monoxide alarms are designed to alert the homeowner when carbon monoxide levels accumulate over a period of time, and will alarm before most people would experience any symptoms of carbon monoxide poisoning. By having an alarm fitted you will be warned before the carbon monoxide presence reaches a dangerous level. In the home or at a commercial facility you can frequently find carbon monoxide has developed from a flame fueled oven, dryer, furnace, grill, space heater or water heater. Once you’ve chosen the right CO detector for your home, you must consider where to place the devices. Installing carbon monoxide alarms with electrochemical sensing technology in the home also provide sufficient protection for residents.