Five tonnes. In the time it took you to read that sentence, that’s the amount of concrete that was produced worldwide. Dating back to around 500 BC, concrete has become a staple material in construction. While the material produces a myriad of possibilities for the industry, the impact of dust pollution caused by the use of concrete can cause a multitude of issues for the health of those using it and the local and global environment. With this in mind, Plant Planet takes a look at the danger of dust pollution, and the ways in which the industry can combat these risks.
Dust pollution defined
Dust pollution is a form of air pollution. Often caused as a by-product on construction sites, dust particles are considered a PM10 pollutant, meaning the particles are invisible to the naked human eye with particles less than 10 microns in diameter.
There are three key types of dust pollution made on construction sites:
- Silica Dust, also known as RCS, is caused by the use of materials such as concrete, mortar, and sandstone.
- Wood Dust is created when working with wood-based materials, particularly with plywood.
- Lower Toxicity Dusts, which are less rich in silica, are made through the use of materials such as gypsum, limestone, marble, and dolomite.
Often, dust pollution is caused by everyday tasks on construction sites. Tasks such as cutting concrete kerbs, drilling, cutting roofing tiles, and abrasive pressure blasting are among the top reasons for the production of dust pollution. Given this, it is unsurprising that dust is one of the key concerns for health and safety officers on construction sites. While it is well known that concrete dust causes risk to health of workers and in the case of long-time work, local residents, it’s also important to consider the impact of dust pollution on local and global environments.
Dust pollution poses a particular threat to sensitive environments (ESA). An ESA is a type of agricultural area that needs special protection because of its landscape, wildlife, or historical value. If these areas are exposed to prolonged construction work, a multitude of issues may occur. These issues, including water pollution, alkaline material dust causing soil pollution, and the damage of crops, can be problematic to both the local ecosystems and the wider environment.
Dust pollution is considered a statutory nuisance in the UK under the 1990 Environmental Protection Act. As such, it is not only ESAs that are affected. Dust pollution in built up areas leads to reduced visibility and smog, causing hazardous air conditions in inner cities. Dust pollution has two potential effects on crops when they are exposed for long periods of time. Firstly, the physical effects include reduced photosynthesis, lowered plant respiration, and increased risk of transpiration through smothering. Secondly, chemical effects include changes to watercourses and soil, resulting in loss of plants and decreased fertilisation of soil. Given the range of environmental impacts posed by dust pollution, it’s important for companies to understand the best methods and practices of dust control on earthmoving sites.
One of the more popular methods of dust control and prevention in construction is the use of water to suppress dust. Jets or streams of water are used to dampen clouds of dust as they arise. For this method of dust control, it is recommended that working sites are dampened an average of three times per day. However, companies should be aware of the risks posed by excess water, including erosion, on the surrounding environment. Alternatively, applying mulch or vegetation to exposed soil in ESAs surrounding the working site can aid the prevention of damage to the surrounding environment. In particular, the hydro-seeding technique, in which a slurry of seed and mulch is applied to the area, is favoured by construction companies. This method is considered to be environmentally friendly and, when implemented properly, can reduce erosion by up to 80%. Whichever method is implemented by construction companies, it is important that it be executed carefully and monitored to ensure that it is working to the best standards.
This article originally appeared in the June 2019 edition of Plant Planet.