CEN/TC 264/WG 28 - Measurement of airborne microorganisms in ambient air

This document contains specifications for active sampling of bioaerosols from exhaust air flowing through a defined cross-section of a stack. It defines general principles that have to be taken into account during an isokinetic sampling campaign for bioaerosols by bubbling the exhaust air through a specific impinger designed for emission measurements.
In this document the application with culturable organisms is specified but the same principle might be applicable for non-cultural based methods (e.g. molecular and/or enzyme-based methods).
The impinger is designed to allow a sample volume flow of 1 m3/h to 1,8 m3/h, or 16 l/min to 30 l/min, respectively, and has been tested with regard to various microorganisms within broad concentration ranges [1; 2; 3; 4]

This document describes the general requirements to be taken into account in planning and implementing plant-related plume measurements of microbial air pollutants. A basic principle of this method is to compare the concentrations in air unaffected by the activities of the plant (i.e. background air sampled upwind of the plant) with the concentration of bioaerosols in air downwind of the plant. It is this comparison that allows an assessment of the plant-related contribution and the mean spatial impact range to be made. As it has so far not been possible to set limit values based on dose-response relationships, the mean impact range is to be used as a first criterion for assessing the environmental impact of a plant.
The scale of work for the plume measurements described is necessary to obtain statistically representative data about the impact range of the plant and/or source, taking into account the great variety of influencing factors.
Plant-related measurements of bioaerosol concentrations in ambient air may be required in a number of regulatory situations. Examples of typical measurement objectives and indicative application scenarios are presented in the document. This method specifies the simultaneous measurement of background and downwind air quality to reduce the risk of invalid comparisons resulting from changing background air concentrations. Another important principle of this method is the requirement for repeated measures to take into account day to day and seasonal variations in the processes governing bioaerosol emissions and dispersion.
The objective is to analyse a given measurement problem and derive the associated requirements for organization, the measurement method, the sampling strategy, the evaluation of the measured data, quality assurance and reporting.

ISO 16000-19:2012 describes the measurement strategy for the detection of fungi in indoor environments.
ISO 16000-19:2012 describes suitable sampling and analysis methods together with a description of the applicability and the interpretation of the measurement results to maximize the comparability of the measured data obtained for a given measurement objective. It does not include details on recording building characteristics or field inspections by qualified professionals which have to take place prior to any microbiological measurement.
ISO 16000-19:2012 is not applicable to a detailed description of the building physics- and building-engineering-related procedures applicable to field inspections. The methods and procedures presented do not allow quantitative exposure assessment with regard to the room occupants.
The application of ISO 16000-19:2012 presupposes the knowledge of ISO 16000-1.

This Technical Specification describes the measurement of moulds in ambient air in order to identify, quantify and characterize bioaerosol pollution in ambient air resulting from emissions from different sources.
The method described specifies the sampling of moulds as part of the suspended particulate matter (SPM, here particles with aerodynamic diameter up to ca. 30 µm) using a filter sampling system with gelatine/poly-carbonate filter combination followed by the culture-based analyses on DG18 agar. The sampling duration can be varied between 10 min to 24 h. The health effect of bioaerosols is not limited to any particle fraction, therefore, this document describes the sampling of moulds as part of the suspended particulate matter as a convention method.
NOTE   The sampling method described in this document in principle is likely to be appropriate for the sampling of actinomycetes and other spore-forming bacteria (resistant to desiccation). For these species a special analytical procedure using different culture media should be applied, but this is not within the scope of this document.
The standard method set out in this Technical Specification is accepted by convention as reference method. The measured quantity, here the number of colony forming units per cubic meter (CFU/m3), is determined by the inlet design of the sampling head, the associated operational parameters and the analytical procedure.
Standardized methods for sampling, detection and enumeration of moulds including standards for sampling strategies are important for comparative assessment of moulds in ambient air. Before doing any measurements a plan for the measurement strategy is necessary (see CEN/TS 16115-2 [5]).
WARNING - The use of this Technical Specification may involve hazardous materials, operations and equipment. This Technical Specification does not purport to address all the safety problems associated with its use. (...)