Understanding Air Pollutants: A Guide to Carbon Monoxide (CO)

What is Carbon Monoxide (CO)

Carbon monoxide (CO) is an odourless, colourless, and tasteless but dangerous gas, and a primary contributor to air pollution. The gas is made up of carbon and oxygen and is highly toxic, capable of causing acute illness and in the most severe cases, death.

Sources

Carbon Monoxide (CO) is formed when materials don’t burn completely; this can occur with the burning of fossil fuels like natural gas, petrol, coal and oil, wood smoke, from car and truck exhausts, as well as through faulty gas heaters, BBQs, ovens, and cooktops.

Carbon monoxide is a major element of exhaust fumes from road vehicles and these emissions are a source of CO, as well as industrial processes such as petroleum refining, oil and gas extraction and chemical production.

Common outdoor objects using hydrocarbons as a fuel can also be a source of CO emissions including some power tools, lawnmowers, generators and open fire.

In the working environment, machinery such as propane powered forklifts, pressure washers and gas powered concrete cutters can contribute to the build up of carbon monoxide in the atmosphere

Environmental Impact

CO is itself a greenhouse gas. When CO is emitted into the atmosphere it adds to the amount of greenhouse gases generated, which of course directly impacts global warming and climate change. As it is a relatively unreactive compound, it does not pose significant threat to plant life. However, it can be quite harmful to oxygen transport systems in humans and other animals.

Health Impact

If inhaled, CO attaches to the haemoglobin in red blood cells, which normally carry oxygen throughout the body. When CO attaches, it “uses up” the oxygen carrying capacity of the red blood cell and thus blocks the transport of oxygen the body needs, ultimately causing a wide range of health problems.

Inhaling low levels of CO can lead to symptoms including nausea, confusion and disorientation, dizziness and headaches. Regularly breathing in low levels can potentially lead to permanent mental or physical problems.

Very high levels of CO can lead to more severe consequences including unconsciousness and death, there are around 60 deaths from accidental carbon monoxide poisoning in England and Wales each year. Whilst extreme levels of CO are uncommon outdoors, there is particular concern for people with pre-exisisting conditions where the heart needs more oxygen than usual when outdoor levels of carbon monoxide are elevated. The greatest risks are indoors or within tents where CO from burning hydrocarbons can build up.

Sensit by Crowcon RAMP

The Sensit RAMP is a robust, remote and reliable low-cost air quality monitoring platform. The device is capable of monitoring up to five gaseous chemical pollutants. The device uses a laser scattering detection method to detect both PM2.5 and PM10 with a range of 1-1000 μg/m3.

The RAMP is suitable for use in a variety of industries including construction, transport, waste, oil and gas, chemical and petrochemical industries.

Understanding Air Pollutants: A Guide to Ozone (O3)

What is Ozone (O3)

Ozone (O3 ) is a highly reactive gas composed of three oxygen atoms. It is both a natural and a man-made product that occurs in both the Earth’s upper (stratosphere), and lower (troposphere) atmosphere. Depending on where it is in the atmosphere, ozone can affect life on Earth in both beneficial and non-beneficial ways. Many people will be familiar with the ozone layer which is naturally occurring in the upper atmosphere and forms a protective layer from the suns rays. The less widely known form of ozone (sometimes referred to as tropospheric ozone) occurs in the lower atmosphere and is one of the most common pollutants impacting the quality of our air.

Sources

In contrast to many air pollutants, almost no ozone is directly caused by human activity. Instead, the ozone is formed in the air where high concentrations of energy interact with oxygen molecules. This can be high energy photons from the sun interacting high up in Earths stratosphere, or lightning in Earth’s lower atmosphere, or from reactions between other pollutants in sunlight. Tropospheric ozone is formed where concentrations of those pollutants are greatest, as sunlight causes reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) – often near cities and industrial areas. Volatile Organic Compounds (VOCs) are generated in a variety of ways, and are often associated with the oil refining and petrochemical industries, whilst nitrogen oxides (NOx) originate from the combustion of fossil fuels in stationary sources, such as heating and power generation, as well as in motor vehicles.

Environmental Impact

Ozone itself is a greenhouse gas. As such, increasing concentrations of ground-level ozone contributes directly to global warming, and is significant as one of the pollutants causing the increase in the overall average temperature of earth’s atmosphere. Ozone is also generally an ingredient in the ‘smog’ which forms over large cities.

Tropospheric ozone has a significant impact on ecosystems, wildlife and plants. It can cause plants, trees and crops to suffer from slowed growth rate and has the potential to cause mass die-off in crops. Tropospheric ozone pollution is often seen to be an urban issue as it is in these areas where it is primarily formed. However, ozone also finds its way to more rural areas, potentially being carried hundreds of miles by wind or forming as a result of other sources of air pollution in these areas.

Health Impact

High levels of ozone gas can cause irritation and inflammation of the lungs, as well as irritate the eyes, nose and throat which can lead to persistent coughing and chest discomfort. This is of particular concern for asthmatic individuals, as ozone pollution episodes can increase breathing difficulties. Studies across Europe, Asia and North America have repeatedly found that risk of premature death increases with higher levels of ozone pollution.

Depending on level of exposure, ozone can cause coughing and sore throats, inflame and damage airways, aggravate existing conditions such as asthma and make the lungs more susceptible to infection.

Sensit by Crowcon RAMP

The Sensit RAMP is a robust, remote and reliable low-cost air quality monitoring platform. The device is capable of monitoring up to five gaseous chemical pollutants. The device uses a laser scattering detection method to detect both PM2.5 and PM10 with a range of 1-1000 μg/m3.

The RAMP is suitable for use in a variety of industries including construction, transport, waste, oil and gas, chemical and petrochemical industries.

Understanding Air Pollutants: A Guide to Nitrogen Oxides (NOx)

What are Nitrogen Oxides (NOx)

Nitrogen oxides (NOx) are some of the most common air pollutants alongside carbon monoxide (CO), ozone (O3), particulate matter (PM2.5 and PM10) and sulphur oxides (SOx).

NOx are poisonous gases derived from nitrogen and oxygen combustion under high pressure and temperatures. The two most common nitrous oxides are nitric oxide (NO) and nitrogen dioxide (NO2). NOx can react with volatile organic compounds to form ground-level ozone and also reacts with atmospheric chemicals, producing PM2.5.

Sources

A major source of anthropogenic emissions of nitrogen oxides into the atmosphere, originates from the combustion of fossil fuels in stationary sources, such as heating and power generation, as well as in motor vehicles, such as internal combustion engines. According to figures from the UK’s Department for Environment, Food and Rural Affairs (DEFRA), road transport accounted for 33% of the emissions of nitrogen oxides in the UK in 2019, and other forms of transport such as aviation, rail, and shipping accounted for 14%. Whilst road transport does account for a third of NOx emissions, there has been a downward trend in emissions as newer vehicles meet more strict emissions standards.

Key industries which generate NOx through their activities are the energy, manufacturing and construction industries. The London Atmospheric Emissions Inventory (LAEI) found that NOx generated from construction accounts for 7.5% of all NOx emissions in the capital.

Environmental Impact

Rapid industrial development in the past 30 years has led to an increase in ambient levels of NOx and other pollutants. The impact of Nitrogen Oxides (NOx), is visible within the smog and typical brown clouds often covering larger cities, which provide poor air quality for the inhabitants. It can also lead to poor visibility, with nitrate particles making the air foggy. NOx emissions also contribute to the creation of acid rain and the formation of ground-level ozone that can damage ecosystems, animal and plant life.

Health Impact

There are both direct and indirect effects on human health as a result of NOx exposure.

High levels of Nitrogen Dioxide (NO2) can be specifically dangerous as they inflame the lining of your airways, and cause a flare-up of asthma or COPD, alongside symptoms such as coughing and difficulty breathing. Those most likely to be affected by these side effects, according to statistics from the British Lung Foundation, include children and older people.

The health effects of NOx become more severe with exposure to higher concentrations or longer term exposure. Prolonged exposure to high levels of NOx has the potential to increase vulnerability to respiratory infections, lead to decreased lung function and contribute to the development of asthma.

Whilst the effects are heightened with longer term and higher levels of exposure, particularly to children, for older people and those with pre-existing conditions, even short term exposure can cause symptoms such as irritation of the lungs in otherwise healthy people.

NOx exposure also has an impact on mortality, with the Department for Environment, Food & Rural Affairs estimating in 2015 that the effects of NO2 on mortality were equivalent to 23,500 deaths in the UK annually.

How Can NOx Be Measured

Nitrogen oxides can be measured through a process known as ‘chemiluminescence’ which is a chemical reaction emitting energy in the form of light. There are over 200 monitoring sites throughout the UK using chemiluminescence analysers.

The largest monitoring network in the UK is the Automatic Urban and Rural Network (AURN), with 127 sites across the country. The AURN is the main hub in the country for compliance reporting against the Ambient Air Quality Directives.

Nitrogen oxides can also be accurately measured in low concentrations using electrochemical sensors – often preferred over alternative methods due to their robustness.

Sensit by Crowcon RAMP

The RAMP is a robust, remote and reliable low-cost air quality monitoring platform. The device is capable of monitoring up to five gaseous chemical pollutants and the electrochemical sensors offer PPB, parts per billion, resolution for both NO and NO2 along with other common air pollutants.

The RAMP is suitable for use in a variety of industries including construction, transport, waste, oil and gas, chemical and petrochemical industries.