Air Quality Monitoring
Common contaminants or pollutants include gaseous pollutants, such as carbon dioxide (produced by occupants and from combustion appliances), volatile organic compounds (released by carpet glues and other common materials), odours and particulates. Good indoor air quality is essential to ensure the health and comfort of occupants.
The adverse health effect to a particular pollutant depends not only on its concentration but also on exposure time to the contaminant. It also depends on the age(s) and sex(es) of persons or groups occupying a space. Current data apply mainly to people in good health and, in the case of working environments, to those between the ages of approximately late teens (16 to 19) and normal UK retirement age.
S.I. Environmental will commonly sample and measure the following parameters to assess the Indoor and Outdoor Air Quality:
Ventilation and Carbon Monoxide:
Where mechanical ventilation is used, there should be a minimum fresh airflow of 8 litres/s per person. Carbon dioxide levels may be investigated to indicate whether adequate fresh air is available in the area – where levels are below 1000ppm it may be assumed that ventilation is adequate.
In addition to having an adequate supply of fresh air, there should be sufficient air movement in the area to avoid stagnation (although not so much as to cause draughts) – current opinion is that the air should flow at 0.1 – 0.15 m/s (and up to 0.25 m/s in the summer).
Ambient temperature should reach 16°C within an hour of starting work and, although there are no legal maximum limits, should be maintained at a “comfortable” level (13 - 30°C) depending on activity level of the operative. Temperature levels should not fluctuate greatly and there should not be a large difference (greater than 3°C) between head-height and ground level temperatures.
Relative humidity should be maintained in the range of 40-70%.
Breathable dust is generally understood to be an aerosol of solid particles, mechanically produced with individually particle diameters of 0.1 microns upwards. Total inhalable dust is the fraction of airborne material which enters the nose and mouth during breathing and is therefore available for deposition anywhere in the respiratory tract. Respirable dust approximates to the fraction of airborne material that penetrates to the gas exchange region of the lung. The main adverse health effects from continuous dust exposure are chronic lung and respiratory system damage.
In addition to the above criteria, S.I. Environmental commonly sample and measure other contaminants which may pollute and degrade the Air Quality, namely: Carbon Monoxide (CO), Volatile Organic Compounds (VOCs), Formaldehyde, Ozone, Benzene, and vehicle engine exhaust emissions.