What Does Area Sampling Mean?
Area sampling is a statistical sampling technique in which conclusions are drawn about an environment by taking samples of the environment from a defined area. In industrial hygiene, area sampling is used to monitor for the presence of hazards within an area. Area sampling is chiefly used to sample airborne contaminants, such as gasses and aerosols.
Area sampling may be limited to general area sampling, in which an entire area (i.e., workspace) is evaluated through a single collection device, or through the collection of samples taken from multiple defined places within the area (cluster sampling). Taking multiple area samples in an environment allows industrial hygienists to identify the source of a contaminant by locating the area where the contaminant exists in the greatest concentration.
Safeopedia Explains Area Sampling
Area sampling is chiefly used by industrial hygienists as a way to assess the general state of an environment; for example, to monitor the amount of noise in the workplace. It is not suitable for monitoring direct exposure to toxins, that type of monitoring requires personal sampling of individual employees. Area sampling is often used as a screening tool to assess whether personal sampling is necessary.
Many area sampling devices monitor a large space for the presence of a contaminant or hazard by actively drawing air through the sampling device. This type of area sampling is useful in occupations in which the presence of a hazard could pose an immediate danger that may not be recognized as quickly via other forms of monitoring. For example, certain types of smoke detectors (air sampling smoke detectors) rely on a form of area sampling that involves automatically drawing-in air through piping/tubing systems in order to constantly monitor areas for fire.
Area sampling is often used to help assess the effectiveness of a given set of hazard controls. For example, a warehouse that uses active ventilation as a way to limit employee exposure to fumes may be inspected using area sampling in order to assess how effective the ventilation system is at removing harmful fumes from the workplace. This may include monitoring whether all areas of the warehouse are equally ventilated.
If airborne area sampling is not possible (e.g., testing a break room for contaminants), the workspace may be divided into multiple discrete areas and the surface of each area tested separately. This type of area sampling is a form of cluster sampling and allows industrial hygienists to draw a reasonable conclusion about an entire workspace by only testing a portion of it.