Environmental monitoring and emission of pollutants in buildings

Occupational hygiene monitoring is monitoring of airborne concentrations of dusts, fumes and gases in the workplace to assess compliance with the requirements of the Control of Substances Hazardous to Health Regulations 2002 (COSHH).

Anthrax monitoring and management is the monitoring and assessing of risks associated with anthrax contamination with the use of animal hair in historic building fabric, e.g. used in binding of lath and plaster.

Anthrax in historic buildings
Anthrax	Anthrax is an infection caused by a biological agent, a bacterium call Bacillus anthracis
Transmission	By spores entering through: broken skin; inhalation; or ingestion.
Symptoms	Malignant pustules – on exposed area of skin. Pulmonary anthrax – through inhalation, typical influenza symptoms. Intestinal anthrax – through ingestion, severe stomach pain, vomiting and diarrhoea.
Sources	Historically horse hair, and has been used in construction, usually as an admixture of plaster, but occasionally on ceilings as an insulant.
Refurbishment of historic buildings	Although regulations to combat anthrax were introduced in 1907, they were virtually ineffectual until the outbreak of the Second World War. So architects, or those involved in refurbishment of historic buildings, should be aware that sampling and analysis would be prudent in buildings over 50 years old to establish whether or not there is a problem.
Hazard group	Bacillus anthracis is in hazard group 3, i.e. it is a biological agent that can cause severe human disease and present a serious hazard to employees; it may present a risk of spreading to the community but there is usually effective prophylaxis or treatment available.

Local exhaust ventilation monitoring is the measurement of the efficiency of local exhaust ventilation systems to ensure effective operation in accordance with the requirements of HSG 54 Maintenance, Examination and Testing of Local Exhaust Ventilation.

Contaminated land monitoring is comprehensive monitoring and investigation to review the site history and to assess contamination and the likely environmental impact associated with it.

Environmental noise monitoring is the measurement of noise exposure in the workplace, to assess compliance with legislation. Following environmental monitoring comprehensive advice and assistance can be provided to reduce noise levels. It includes measurement of ambient noise levels for a variety of purposes such as nuisance assessment, preparation of planning applications or selection of control measures.

Environmental monitoring for volatiles: Fungal volatiles affect the health of the occupants by causing, for example, nasal irritation and feelings of stuffiness. Moulds can produce a variety of volatile substances, including alcohols and ketones such as 3-methylbutanol, octen-3-one, octan-3-one, octain-3-ol, 2-octen-1-ol, 1-octen-3-01 and 1,10-dimethyl-trans-9-decalol (geosmin). Other compounds such as 2-methyl isoborneol and 2-methoxy-3-isopropylpyrazine may contribute to 'musty', 'mouldy' or 'earthy' odours associated with mould growth in damp buildings. The principal volatile of moulds in damp buildings is ethanol.

Environmental monitoring for mycotoxins: Toxins produced by moulds are called mycotoxins. Mould spores contain a variety of biologically active molecules called mycotoxins other than allergens. There is evidence that inhalation of fungi - particularly those that produce mycotoxins - results in immunological disregulation, with potential neurological effects, i.e. interference with pulmonary macrophage function (lungs policing). It is also possible that straightforward mycotoxicosis (a disease caused by the inhalation of mycotoxins) from inhalation exposure occurs under some circumstances.

Toxic substances in paintwork

The purpose of this type of environmental investigation is to study and identify the possibility of any hazardous materials associated with the painted building fabric. This information may then be used to determine appropriate methods to prevent exposure to harmful substances and allow appropriate disposal of waste materials, before commencing remedial works.

If lead is detected in any of the coatings tested, the proposed works may come under the scope of the Control of Lead at Work Regulations 2002.

Samples of the paintwork, down to bare substrate, should be taken for analysis to determine if any hazardous substances are present. All permutations of paint coatings should be sampled as historic coatings may be more likely to contain hazardous constituents than modern coatings.

The samples would be analysed for the following substances:

Aluminium	Manganese	Antimony	Nickel
Arsenic	Lead	Cadmium	Selenium
Chromium	Thallium	Cobalt	Tin
Copper	Vanadium	Iron	Zinc

Risk assessment and method statement documentation should be prepared, along with any practical guidance in controlling release and exposure, as required under the scope of the Control of Lead at Work Regulations 2002 in the case of lead compounds.

Guano contamination and health implications

Pigeon guano (excrement) can carry several potentially infectious diseases, such as:

• salmonella;
• tuberculosis; and
• ornithosis (a mild form of psittacosis - pneumonia-like symptoms).

Guano is also a source of allergens that can cause respiratory ailments like pigeon fancier's lung and allergic skin reaction.

Histoplasmosis is caused by a fungus (Histoplasma capsulatum) and can affect both humans and animals. Infection in humans occurs when airborne fungal spores are inhaled, especially after the nesting has been disturbed. Most infections are mild and produce either no symptoms or a minor influenza like illness. Dusts containing Histoplasma capsulatum spores can be aerosolised during construction, excavation, or demolition. Once airborne, spores are easily carried by wind currents over long distances.

Pigeon droppings appear to be the most important source of the fungus Cryptococcus neoformans in the environment causing cryptococcosis. The fungus is largely found in accumulated droppings around roosting and nesting sites, for example, roof spaces, weather boarding, guttering, chimney stacks, window cills, cupolas, ledges and water towers. It has been found in as many as 84% of samples taken from old roosts. Both old and dry, bird droppings can be a significant source of infection.

Like histoplasmosis, cryptococcosis infections are mild and may be without symptoms. Persons with weakened immune systems, however, are more susceptible to infection. The disease is acquired by inhaling the yeast-like cells of the fungus.

Candidiasis: these illnesses can be spread to people through contact with pigeon droppings, dandruff and feathers, pigeon parasites, or where dead infected pigeons get into food or water sources. The most serious health risks arise from disease organisms that can grow in the nutrient-rich accumulations of bird droppings, feathers and debris under a roost - particularly if roosts have been active for years.

External parasites also may become a problem when infested birds leave roosts. Pigeon faeces represent a health and safety hazard for occupants, employees and workers who have to remove them or work in their vicinity. So they are a special problem in the renovation of buildings where large accumulations have been allowed to build up.

Health and safety problems are also caused by the build-up of faeces, as they can make walkways and ledges slippery and footing unsafe, hindering proper maintenance. This may also be a particular problem during building works and renovation.

Other contaminants/hazardous materials

Other contaminates in historic fabric may need to be tested, including:

• lead piping and roofing materials;
• structural timbers for possible arsenic / heavy metal / organic preservatives;
• electrical components for possible PCB or mercury presence;
• fibrous materials (other than asbestos);
• any residual materials as a result of previous uses of the buildings and site; and
• sharps - needles and sharps, razors should be identified in the building and marked on plans for disposal accordingly.