Indoor air quality report

Aim

Envirocheck (UK) Ltd were requested to carry out an indoor air quality survey at the British Library Building, Euston, London.

The visit took place on the 26 January 2004, by Mr Abbas Shakeri - Environmental Consultant.

The aim of this survey was to conduct direct measurement tests in order to establish the quality of the indoor air within the reading room in connection with total particulate matter (i.e. dust), Microbial contamination and Volatile Organic Compounds (VOCs), we also conducted a test for levels of Formaldehyde.

Another two office locations were also tested, however the test within these areas was to ascertain the comfort factor, particle levels and microbial levels.

We conducted the following tests at the locations listed below:

1. Main reading room lower and upper level

1. Microbial Level (x 2 locations)
2. Particle Analysis
3. VOC's Analysis (x 2 locations)
4. Formaldehyde Analysis
5. Comfort Factor, include (Co₂, Co, Temperature & Humidity)

2. Reader Registration Office (Room 22)

1. Particle Analysis
2. Comfort Factor, include (CO₂, CO, Temperature & Humidity)

3. Reader Registration Office

1. Particle Analysis
2. Comfort Factor, include (CO₂, CO, Temperature & Humidity)

Method statements

Particle analysis

The particle content of the air was analysed using a Dust Trak System. The Dust Trak system samples the air to analyse the levels of particles down to 0.001mg/m³.

VOCs

The Client should note that the samples taken (Volatile Organic Compounds) within the reading room, were analysed by gas chromatography-mass spectrometry (GC-MS), which is essentially a screening technique used to identify and quantify volatile organic compounds.

Bacteria and fungi/yeast level analysis in the air

The levels of bacteria and fungi are determined by sampling a preset volume of air 500 litres onto 90mm petri dishes containing the specific growth media. Two different types of growth media are used at each location. A Merck air sampling system was used for this process. All petri dishes are analysed by a UKAS approved laboratory.

Temperature and humidity analysis

These parameters are measured using a Q-Trak IAQ Monitor.

Averaged particle analysis results

Comments:

The levels are very low and represent a very clean environment. The above data also shows that the filtration system is effective and suitable for such environments.

Temperature and relative humidity results

Humidity -

Humidity can have adverse affect on the growth of mould and dust mites within an area if allowed to become too high. Rapid growth occurs when levels of humidity increase above 70%, with great effects to respiratable illnesses such as asthma. In the same aspect if levels of humidity become too dry, below 30% this too can have adverse effects, with some people susceptible to sore throats due to the dryness of the air.

The optimum level of humidity should be 30 - 70%, with much dependant on the indoor environment in question, and the seasonal variation as to the best level for the area in question.

Temperature -

Temperature levels within an indoor environment will vary greatly on the time of year and personal preference. However increased temperature within a confined space such as an indoor environment can instigate a more suitable environment for the growth of unwanted bacteria and fungi.

Analysis must be carried out in close collaboration with other parameters analysed to determine characteristics of change.

In general it would be reasonable to maintain a temperature of around 19°C within a building.

Carbon dioxide and carbon monoxide results

Carbon dioxide -

Carbon dioxide is present in the natural environment, being produced by combustion of biological processes. Carbon dioxide is present at typical levels of about 300 ppm in the ambient urban environment though this can rise substantially inside occupied buildings. The Health & Safety Executive has set an Occupational Exposure Standard (OES) of 15,000 ppm as a 15-minute time-weighted-average. OESs are set at a level at which there is no indication of any risk to health and employers are simply expected to ensure that OES limits are not exceeded.

However, carbon dioxide levels are often used as a guide to whether or not a space has a sufficient quantity of fresh air. The International Energy Agency advice is as follows: -

1. levels of carbon dioxide below 1000 ppm indicate good ventilation
2. levels between 1000-2000 ppm indicate slightly low rates of ventilation
3. levels above 2000 ppm suggest poor rates of ventilation, which can produce a stuffy feeling, encourage odours to linger and give rise to complaints of stale air.
4. levels above 5000 ppm indicate very poor control of air quality and an urgent need for remedial action.

Carbon monoxide -

Carbon monoxide results from the incomplete combustion of fossil fuels. CO combines with the haemoglobin in the blood thus reducing the oxygen-carrying capacity of the blood. Natural ambient background levels generally range between 0.01 and 0.2 ppm, but concentrations in urban areas are higher and vary greatly with the weather and traffic density.

The OES for carbon monoxide is 200 ppm (15-minute reference period). The World Health Organisation (WHO) recommended guideline for CO is 90ppm averaged over a 15-minute period. WHO Guidelines are designed to protect the most vulnerable groups of the population and are therefore not considered to be particularly relevant to assess the potential health effects of pollutants on the general; population as opposed to workers.

Microbiological sample analysis

Comments

At the time of sampling in locations 1 & 2 the cleaning team were using vacuum cleaners for cleaning the area. We feel that the high levels of bacteria detected are as a result of this action. However we would recommend that further samples are taken from the area on a regular basis.

Volatile organic compounds and formaldehyde results

No Volatile Organic Compounds were detected.

Formaldehyde level present within the area was well below the limit of 2.5mg/m³ OEL listed in EH 40/2003.

Conclusion

The high bacterial levels detected within the reading room could be as a result of the cleaning (vacuum) during the sampling period.

All other readings were satisfactory at the time of survey, however we would recommend that such a building must be monitored for the quality of indoor air on a regular basis.

We feel that a regular monitoring programme could provide sufficient data in order to assure occupants of this buildings' indoor air quality.

Recommendations

We recommend that the indoor air quality of the rooms are tested at least six-monthly basis together with the associated ductwork, resulting in a history of the Room conditions.

From the above, should systems start to deteriorate and/or defects occur it can be rectified prior to it having an adverse effect on the air quality. The valuable data can also be used to demonstrate the efficiency and effectiveness of the maintenance programme.

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