The presence and impact of pollution is a global issue. However, whilst many media outlets and the public in general focus around the effects of greenhouse gas pollution, and global warming, there are in fact many other types of pollution that have an impact on society. One of the areas where there is a lot of (different types of) pollution is within the construction industry. This article looks at the different types of pollution that occur on a construction site and what is being done to lower the pollution levels.
Air pollution is one of the biggest polluters within a construction site and comes in many forms, although the three most common pollutants include large amounts of dust, the emission of a number of gases, and the presence of large amounts of smoke.
Air pollution is not limited to just the build itself, and can also occur during excavation, land clearing, demolition, the burning of materials, the operation of vehicles and equipment, and when construction workers are working with toxic materials.
Given the nature of the work undertaken on various construction sites, dust is one of the main causes of air pollution from these sites. Dust is categorized by any particulate matter that is smaller than 10 microns in diameter. There are many reasons why dust is the biggest air pollution issue.
First off, the materials that the builders are working with, such as concrete, cement, wood, stone and silica, are prone to releasing dust and can be carried over wide areas. Additionally, diesel engines, and on-site equipment that uses diesel, releases dust-sized particulate matter in the form of soot, sulphates, and silicates into the air.
Diesel engines and equipment are also responsible for the release of toxic gases into the air. Aside from the dust-sized particulate matter, the use of these machines also releases carbon monoxide, hydrocarbons, nitrogen oxides and carbon dioxide into the atmosphere. Many of the other hazardous chemicals used on construction sites, such as oils, glues, thinners, and paints, can release toxic fumes into the atmosphere as well.
Smoke is often brought about by the workers on the building site burning materials on site, but this is becoming an outdated (and banned in some places) procedure. A lot of health hazards can bestow the local public, especially those with respiratory conditions, if a large amount of smoke enters the local residential areas.
This becomes a significant hazard if materials that give off black smoke (such as plastics) are burnt as well. In addition to this, if the fire is not kept under control, it can pose further risks to those on and off the site.
There are many measures in place to prevent or minimize air pollution. As dust pollution is the biggest problem, more measures are in place to prevent dust entering the local environment more so than other forms of air pollution. However, for smoke, not burning anything on site is the key way of preventing the pollution from occurring, and in some countries, such as the UK, the contractors can now be fined for burning materials on site.
For diesel engines, it is not as straightforward, but there are many measures being put in place around the world to improve diesel emissions. As it stands, the best way to minimize these emissions is through using low sulphur diesel in all equipment and engines and improve existing equipment with the latest particle filters and catalytic converters.
Now on to the dust preventative measures, of which there are many. The main ways to minimize the impact of dust pollution is through dust screens that enclose the building under construction and a solid barrier around the whole site, enclosing the material hoist and debris chute within a dust screen during construction, spraying water onto debris before it goes down a debris chute, spraying water on façade when grinding work is being performed, equipping a vacuum cleaner to the equipment during grinding, and covering up the material where possible — be it during transit, or when there are piles of building materials on site.
Water pollution is another problem from construction sites, and is caused by the run-off of debris, dirt, diesel, oil, paints, and other harmful chemicals into the drains (if in an urban site) or into a local waterway (if the construction site is more rural). General wastewater from construction sites can also cause issues with the local water systems.
The main water pollution issue is the deposition of construction materials into waterways that feature wildlife or are connected to waterways with wildlife in them. Not only can the toxic chemicals get into the water, but pollutants can also soak through the ground and leach into the groundwater. Many groundwater sites are also used for human consumption and contaminated groundwater is a lot harder to treat than surface water.
Another aspect to water pollution is during the land clearing process. When the land is cleared, the silt and soil can erode and travels as sediments which enter the local waterways — and this can destroy the local wildlife by making the waterway turbid and restricting the amount of sunlight entering the waterway. On the other hand, the presence of building materials in high-urban environments can lead to blockage of the underground sewers, which then poses further health risks.
The main ways to prevent water pollution include; minimizing the land disturbance (whilst leaving as much vegetation as possible during the excavation process), covering up all drains on a construction site, using non-toxic chemicals where possible (and tightly cover and monitor toxic substances when they have to be used), covering building materials so the risk of them being washed away during rain (or other natural conditions) is minimized, and collecting and treating the wastewater before it is discharged as an effluent — where the clean water can be discharged and the sediment sludge can be collected and thrown away.
Everyone knows that there is a lot of noise produced by building sites. This noise pollution mainly comes from vehicles, heavy equipment and machinery, but it can also include physical human work such as hammering, as well as loud radios and shouting throughout the construction site. Not only is a large amount of noise an issue to any residents in the locale of the construction site, but loud noises can also disturb the natural cycles of animals, which leads to their normal habitats becoming usable.
The main preventative measures for tackling noise pollution include movable noise barriers, putting up wall-like structures to act as sound shields, carefully handling materials and through the use of quiet power tools and equipment.
Sustainable Build: http://www.sustainablebuild.co.uk/pollutionfromconstruction.html
Newham Council, London: https://www.newham.gov.uk/Pages/Services/Pollution-control-construction-sites.aspx
Environmental Protection Department, Hong Kong: https://www.epd.gov.hk/epd/english/greenconstruction/poll_pro/g_building.html
Kansas Department of Health and Environment: http://www.kdheks.gov/nps/resources/notes_ww/eroscons.pdf