CEN/TS 16115-2:2016

SLOVENSKI STANDARD
01-julij-2017
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Ambient air - Measurement of bioaerosols - Part 2: Planning and evaluation of plant-
related plume measurements
Außenluft - Messen von Bioaerosolen - Teil 2: Planung und Auswertung von
anlagenbezogenen Fahnenmessungen
Qualité de l’air ambiant - Mesurage de bioaérosols - Partie 2 : Planification et évaluation
des mesurages dans le panache de fumée des installations industrielles
Ta slovenski standard je istoveten z: CEN/TS 16115-2:2016
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TS 16115-2
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
December 2016
TECHNISCHE SPEZIFIKATION
ICS 13.040.20
English Version
Ambient air - Measurement of bioaerosols - Part 2:
Planning and evaluation of plant-related plume
measurements
Qualité de l'air ambiant - Mesurage de bioaérosols - Außenluft - Messen von Bioaerosolen - Teil 2: Planung
Partie 2 : Planification et évaluation des mesurages und Auswertung von anlagenbezogenen
dans le panache de fumée des installations Fahnenmessungen
industrielles
This Technical Specification (CEN/TS) was approved by CEN on 5 October 2016 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 16115-2:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Key principles of sampling and assessment . 9
5 Measurement objective and applications . 10
5.1 General . 10
5.2 Indicative applications . 10
6 Relevant plants . 11
7 Measurement parameters. 12
8 Meteorological conditions . 12
8.1 General . 12
8.2 Determination of meteorological conditions prior to the ambient air measurement . 13
8.3 Determination of meteorological conditions during the ambient air measurement . 13
9 Determination of upwind concentration . 13
10 Measurement strategy for plume measurements . 14
10.1 General . 14
10.2 Principle and objective of plume measurements . 15
10.3 Contextual information . 15
11 Measurement area, sampling locations and siting . 16
11.1 General . 16
11.2 Measurement area . 16
11.3 Sampling locations: Siting . 16
11.3.1 General . 16
11.3.2 Sampling location: Siting for point sources . 16
11.3.3 Sampling location: Siting for area sources and extended sources . 18
11.3.4 Sampling location: Siting for central traverse model . 20
11.3.5 Sampling location: Siting in the case of cold air drainage . 20
12 Measurement period, sampling frequency and sampling duration . 20
13 Evaluation . 21
14 Measurement report . 21
15 Quality assurance . 22
15.1 Plausibility check of individual values . 22
15.2 Quality criteria . 22
16 Limitations . 22
Annex A (informative) Measurement parameter and indicator organisms . 23
A.1 General . 23
A.2 Notes on the use of Table A.1 . 23
Annex B (informative) Determination of the measurement parameter-specific mean impact
range . 29
B.1 General . 29
B.2 Median concentration – mean impact . 29
B.3 Determination of mean impact range . 29
B.4 Arithmetic mean of upwind concentration . 31
B.5 Determination of receptor-oriented plant impact . 31
B.6 Assessment of a potential plant-related impact . 31
B.7 Sensitive receptor and determination of peak concentration . 32
B.8 Example calculation . 32
B.8.1 General . 32
B.8.2 Fan measurement . 33
B.8.3 Central traverse measurement . 35
B.8.4 Comparison of results of both methods . 36
B.9 Software . 36
B.9.1 General . 36
B.9.2 Application instructions . 37
Annex C (informative) Minimum requirements for plume measurements . 38
C.1 General . 38
C.2 Minimum requirements for the determination of the spatial concentration
distribution . 38
C.3 Minimum requirements for the determination of the median to calculate the mean
impact range . 38
C.4 Minimum requirements for the determination of the 96th percentile concentration . 38
C.5 Minimum requirements for the determination of the arithmetic mean . 39
Annex D (informative) Documentation of measurement preparation (measurement plan) . 40
Bibliography . 41

European foreword
This document (CEN/TS 16115-2:2016) has been prepared by Technical Committee CEN/TC 264 “Air
quality”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
CEN/TS 16115 consists of several parts dealing with the determination of bioaerosols in ambient air:
— Part 1: Determination of moulds using filter sampling systems and culture-based analyses;
— Part 2: Planning and evaluation of plant-related plume measurements.
The basic requirements of the determination of bioaerosols are first published as Technical
Specifications. The precision and the performance characteristics of bioaerosol measurements should
be determined in comparison and validation trials in order to validate the method(s). Based on the
validation results the Technical Specifications can be transferred to European Standards. For this
purpose it is intended to apply for mandated support by the European Commission and the European
Free Trade Association using the Technical Specifications as a basis for validation measurements.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
Airborne particles of biological origin are called bioaerosols. Natural and anthropogenic sources for
bioaerosols are widely distributed in the environment. Anthropogenic sources can for example be
agriculture or waste treatment activities.
The purpose the measurement planning here described is to determine the mean plant- and/or source-
related impact range of microbial air pollutants. 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 criterion for assessing
the environmental impact of a plant.
The scale of work for the plume measurements here 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. Whilst a reduced measurement effort is possible in principle, this will lead
to an increased measurement uncertainty.
The objective of measurement planning 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.
The requirements set out in this technical specification are to ensure that plant-related ambient air
measurements of microbial air pollution are planned in such a way as to enable a given task to be
processed with sufficient accuracy and at justifiable cost. The aim is to ensure that the measured data
obtained meet the applicable standards for representativeness and hence, enable maximum possible
comparability.
The procedure described in this document is based on VDI 4251 Part 1 [1].
1 Scope
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.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
CEN/TS 16115-1, Ambient air quality - Measurement of bioaerosols - Part 1: Determination of moulds
using filter sampling systems and culture-based analyses
EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
(ISO/IEC 17025)
EN 13098:2000, Workplace atmosphere - Guidelines for measurement of airborne micro-organisms and
endotoxin
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
additional impact
contribution of the plant under study to the ambient air pollution at a receptor point
3.2
area source
emitting area of a relevant size, normally horizontally orientated; area sources are distinguished into
sources with a defined volumetric flow rate (e.g. biofilter, aerated composting windrow) and sources
without defined volumetric flow rate (e.g. landfills, agricultural land)
3.3
bioaerosol
airborne particles of biological origin
[SOURCE: EN 13098, 3.3, modified]
Note to entry 1: The term bioaerosols as used in this standard designates all airborne accumulations of particles
carrying, containing or forming fungi (spores, conidia, hyphal fragments), bacteria, viruses and/or pollen as well
as their cell wall components and associated metabolites (e.g. endotoxins, mycotoxins) ([5]; [6]).
3.4
concentration
as defined in this standard denotes the number of microorganisms in concentration of bioaerosol
expressed in the according units e.g. in colony forming units (CFU) per unit volume or Endotoxin units
(EU) per volume
3.5
emission
microbial air pollution emanating from the plant under review; the emission is determined at the point
of transition of the bioaerosols from the emission source to the atmosphere; the result of an emission
measurement is the bioaerosol flow calculated as the product of the concentration and the volumetric
flow rate; emission concentrations of bioaerosols are indicated in CFU/m , emission mass flows in
CFU/h, for instance; the bioaerosol flow is also used as a basis for estimating the geometric centroid of a
source or source system of a plant or for impact forecasts
3.6
extended source
emission source of a spatial structure consisting of a number of individual sources (e.g. Figure 2)
3.7
impact range
distance at which a plant impact can still be detected
Note to entry 1: The plant- or source-related measurement parameter-specific mean impact range described here
designates the distance from the source at which the ambient air concentration of a measurement parameter has
declined to the level of the upwind concentration. The “mean impact range” is determined with the aid of an
exponential depletion curve as described in Annex B.
3.8
indicator organism
microorganisms that are characteristic of the emission of a plant and can be detected by currently
available sampling and analysis methods. Indicator organisms that are characteristic of a defined source
(process) may also be present – usually in small concentrations – in the ambient air outside the zone of
influence of this source; this is due to the ubiquitous nature of many microorganisms
3.9
measurement parameter
constituent of the ambient air for which a defined measured quantity is to be determined; in the present
case, the microbial air pollutant of interest, e.g. bacteria, moulds
3.10
measurement strategy
methodology applied for the spatial and temporal sampling of air pollutants in order to obtain valid
(representative) random samples in terms of the task at hand; the measurement strategy mainly
comprises the definition of the measurement area, sampling locations, measurement parameters, time
of measurement and the sampling frequency and duration; secondary factors influencing the selection
of the measurement strategy include, for instance, the meteorological conditions, sampling equipment,
resource intensity for the necessary analyses and evaluation; moreover, tertiary influencing factors
such as unfavourable conditions during frost events may have to be considered
3.11
)
mesophilic
property of microorganisms which depend on a temperature of between 20 °C and 45 °C for optimum
growth and reproduction
3.12
microbial air pollutant
concentration of airborne microorganism which are not naturally present in the respective species
distribution and/or respective quantities in the ambient air at the given location and time
3.13
microorganism
any microbiological entity, cellular or non-cellular, capable of replication or of transferring genetic
material, or entities that have lost these properties
[SOURCE: EN 13098, 3.16, modified)
3.14
moulds
filamentous fungi of the taxonomic classes zygomycetes, ascomycetes and deuteromycetes (fungi
imperfecti) producing a mycelium and spores so that they become macroscopically visible as a
(frequently coloured) mould layer
Note to entry 1: Taxonomically, moulds do not represent a uniform class.
Note to entry 2: The various groups of filamentous fungi form conidia (deuteromycetes) or sporangiospores
(zygomycetes) and, more rarely, ascospores (ascomycetes). In practice, all these reproductive stages are
subsumed under the term “spores”.
3.15
point source
emission source occupying a small “point-shaped” area and having a concentrated output. Point sources
are classified into sources with a defined volumetric flow rate (e.g. exhaust air stack) and sources
without defined volumetric flow rate (e.g. building openings)

) The psychrophilic, mesophilic and thermophilic temperature regions do not have clear cut-off points and are
differently defined in the literature.
3.16
)
psychrophilic
property of microorganisms which depend on a maximum temperature of around 20 °C for optimum
growth and reproduction
3.17
sampling location
local point within a defined measurement area at which sampling is performed
3.18
sensitive receptors
humans, animals and plants, soil, water, cultural and other assets as well as the atmosphere itself that
may be exposed to harmful environmental impacts caused by air pollution
3.19
tenacity
resistance to chemical and physical environmental influences (temperature, chemicals, radiation, open
air factors, etc.)
3.20
3)
thermophilic
property of microorganisms which depend on a temperature of above 45 °C to about 80 °C for optimum
growth and reproduction
Note to entry 1: Temperature optimum for hyperthermophilic species: above 80 °C; for extremely thermophilic
species: 70 °C to 80 °C; for strictly thermophilic species: above 60 °C, for thermotolerant species: below 45 °C
(growth above 45 °C possible).
3.21
upwind concentration
by convention, the upwind concentration (Luv) in terms of this standard is determined by a
concentration measurement at a sufficient distance upwind of the plant performed simultaneously with
the downwind (Lee) ambient air measurements; any direct influences of other plants on the measured
upwind concentration shall be minimized
3.22
downwind concentration
by convention, the downwind concentration in terms of this standard is determined by concentration
measurements at distances downwind of the plant performed simultaneously with the upwind ambient
air measurements
4 Key principles of sampling and assessment
A variety of industrial (e.g. waste management) and agricultural (e.g. animal production) activities are
known to generate bioaerosols and release them into ambient air (Annex A). This document describes a
method for determining the contribution made by such activities to the concentration of bioaerosols in
ambient air.
) The psychrophilic, mesophilic and thermophilic temperature regions do not have clear cut-off points and are
differently defined in the literature.
) The psychrophilic, mesophilic and thermophilic temperature regions do not have clear cut-off points and are
differently defined in the literature.
Bioaerosols are ubiquitous in ambient air. They are generated naturally (e.g. as a result of the air-borne
dissemination of fungal spores) and anthropogenically. A basic principle of this method is to compare
the concentration of bioaerosols 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 bioaerosol
emission source of interest (the plant). It is this comparison that allows an assessment of the plant-
related contribution to be made.
Concentrations of bioaerosols in upwind and downwind air of an emission source are both subject to
temporal variation (see Clause 12). The rate of bioaerosol emissions from natural and anthropogenic
sources may vary diurnally or seasonally depending upon the source and the controlling factors
involved. Further temporal variation in air quality may be influenced by the prevailing meteorological
conditions which can influence the dispersion characteristics and viability/culturability of bioaerosols.
This method specifies the simultaneous measurement of upwind concentration and downwind air
quality to reduce the risk of invalid comparisons resulting from changing upwind concentration 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. In essence, the validity of the assessment of the plant-related contribution is enhanced
as the number of measurement days increases.
Spatial variation (see Clause 11) in the concentrations of bioaerosols in air is potentially a significant
factor influencing our ability to determine the impact of the bioaerosol emission source of interest (the
plant) on ambient air quality. Localized differences in air quality are driven by a number of factors
including: the spatial arrangement of sources of bioaerosol emissions; changes in wind direction and
meteorological conditions affecting dispersion; topographical features affecting dispersion; and
4)
environmental factors influencing microbiological die-off processes [2]. The method described in this
document seeks to characterize and account for spatial variability in several ways. In simple terms, the
bioaerosol concentration is normally expected to decline with distance downwind from source (as a
result of dispersion, deposition and die-off processes), ultimately returning to a value approximating
the upwind value. This pattern can be characterized by sampling upwind and at a number of different
distances downwind of the emission source. A simple linear traverse may serve this purpose but may
not be able to account for localized variability at the time of sampling induced by changes in wind
direction and multiple emission sources. A fan-like arrangement of sampling points is more likely to
capture such spatial and temporal variability.
5 Measurement objective and applications
5.1 General
The prime objective of measuring plant-related microbial ambient air pollution is to identify the
ambient air microbial concentration contributed by the plant. More specific objectives are to be
formulated depending on the application.
5.2 Indicative applications
Possible indicative applications of plant-related plume measurement are:
a) Licensing application procedure

4)
Die-off processes are mainly determined by the tenacity of the microorganism. Main factors influencing the
tenacity of airborne microorganisms can include the type of carrier particles, relative humidity, temperature, open
air factors such as UV radiation and micro-biocidal atmospheric trace gases.
An assessment of the bioaerosol concentration at a neighbouring environment, e.g. population
areas or other sensitive receptors may be needed as part of the licensing procedure, e.g. for new
constructions or for an extension to or major modifications of an existing plant.
Concentration levels measured at selected sites (e.g. sensitive receptor locations) may be used for a
5)
comparison with the results of emission impact forecasts ). To this end, it is imperative that the
measurement strategy be selected such as to cover the temporal, spatial and meteorological
reference frame of the associated emission impact forecast.
b) Verifying compliance with licensing requirements within the scope of plant monitoring
When monitoring bioaerosol emissions and/or ambient air bioaerosol concentrations with regard
to licence compliance of the operations under review, the data to be determined derive from the
collateral licensing requirements. Details of measurement planning such as measurement area,
number of sampling locations, number of measurements, measurement parameters and plant
operating conditions should be coordinated with the licensing authority.
c) Verifying the effectiveness of emission control measures or monitoring operational changes
Remediation measures or major changes in a plant’s operations may have a significant influence on
the emissions of a plant. In addition to measuring the emissions from area or point sources,
ambient air measurements should be considered especially in cases where the (reduced) additional
environmental impact is to be documented.
d) Complaints
In the case of complaints, any additional impacts upon the neighbouring environment, e.g. general
population or other sensitive receptors (e.g. food processing facility, hospital) are to be determined.
The choice of measurement parameters is governed by the type of sensitive receptor, e.g. if the
sensitive receptor is the neighbouring population, health relevant measurement parameters should
be included (see Table A.1).
6 Relevant plants
Bioaerosol emissions may originate from all plants in which materials containing microorganisms or
their components are handled. Their dispersal is primarily influenced by the meteorological conditions
and the tenacity of the species involved. The most comprehensive experience with bioaerosol emissions
available so far relates to biological waste treatment plants. Relevant plant types in different industrial
sectors are listed below:
a) Waste management and disposal
1) Composting and anaerobic digestion plants
2) Materials recovery and reprocessing plants (recyclable wastes)
3) Waste transfer stations
) Dispersion models are available for modelling the dispersal of air pollution, e.g. for particles and odours. See for
example in Germany www.austal2000.de and VDI 4251-3 and for the Netherlands the New National Model;
(http://www.infomil.nl/onderwerpen/klimaat-lucht/luchtkwaliteit/regelgeving/wet-
milieubeheer/beoordelen/koppeling/nieuw-nationaal/)
4) Mechanical-biological treatment plants for residual waste (MBT)
5) Landfill sites
b) Agriculture
1) Livestock production; storage, treatment and land application of animal faeces
2) Plant production and processing
3) Animal feed production
c) Food production
d) Other areas
1) Waste water treatment plants
2) Biological exhaust air cleaning units, cooling towers
7 Measurement parameters
The selection of the measurement parameters is governed by the expected emission and the
measurement objective.
Table A.1 gives an overview of the microorganisms (groups) likely to be emitted in relevant quantities
from the various plant types. Generally, plant-specific measurement parameters (indicator organisms,
e.g. thermophilic actinomycetes for composting plants or staphylococci for livestock buildings) or a
qualitative analysis are well suited to the assessment of the plant impact. In contrast, microorganisms
(groups) that are ubiquitous in the ambient air or that are temporarily present at elevated
concentrations are less suited for use as measurement parameters for ambient air measurements, as
their concentration levels will not differ significantly from the upwind concentration even at a relatively
short distance from the source.
In the individual case, it should, however, be checked whether the selected measurement parameters
are to be used for a specific assessment of a suspected plant impact or whether an additional health
relevance is to be made with regard to an additional impact of microbial air pollutants at the sensitive
receptor location.
8 Meteorological conditions
8.1 General
As the prevailing meteorological conditions have a significant influence on the measurement results,
they shall be determined prior to and during the measurements, considered in the evaluation of the
results and documented.
Except for justified cases, the measurements described in this document should not be performed
during periods of rain or frost. Measurements under such meteorological conditions make sense for
certain measurement objectives and/or are unavoidable in long-term sampling projects, but require a
special measurement strategy which is not the subject of this document.
All measurement strategies described in this document are not applicable to ambient conditions
involving highly variable wind directions, as the minimum requirement for the wind direction specified
in Clause B.3 (wind flow in the direction of the sampling equipment over 80 % of the sampling
duration) cannot be satisfied under such conditions.
Measurements for the determination of the mean impact range (see Annex B) should also not be
performed under conditions of unstable thermal stratification of the atmosphere (major solar radiation
with high surface temperatures at minor advection).
8.2 Determination of meteorological conditions prior to the ambient air measurement
The determination of the meteorological data prior to the ambient air measurement serves to define the
orientation of the fan-like sampling arrangement and the position of the sampling locations.
Prior to the ambient air measurements, weather forecasts for the measurement area on the planned
measurement day shall be obtained. In this connection, potential cold air drainage is to be taken into
account, especially when sensitive receptors are located in the cold air drainage path. Potential cold air
drainage shall be accounted for in the selection of the measurement strategy and especially in the
selection of the measurement area and the sampling locations.
8.3 Determination of meteorological conditions during the ambient air measurement
When performing plant-related measurements of microbial air pollutants, the meteorological
influencing parameters shall be recorded throughout the sampling duration in order to be able to put
the observed ambient air concentrations into perspective.
Meteorological parameters to be determined include:
— wind speed,
— wind direction,
— temperature,
— relative air humidity,
)
— atmospheric stability .
The above meteorological parameters shall be measured under conditions of free and unhindered air
flow to the meteorological station which should be located at a representative site within the
measurement area, preferably between the source and the ambient air sampling locations. The
measurement scale derives from the measurement objective. The meteorological data from national
meteorological services can provide helpful information taking into account the validity for the
measurement area. Documentation of the actual meteorological conditions prevalent during the
measurement is imperative.
9 Determination of upwind concentration
The determination of the upwind concentration is required to compare the measured ambient air
concentrations at the sampling locations with the simultaneously measured local upwind concentration
level for obtaining information on the relative additional impact contributed by the plant (see
Clause 10). Therefore, measurement of the upwind concentration plays an important role in
determining plant-related ambient air bioaerosol concentrations. To rule out any plant influence on the
local upwind concentration, the measurements shall be performed upwind of the plant.

) The atmospheric stability has an influence on the measurement results. Input variables are the hour of the day,
the wind speed and the cloud cover at the time of the measurement. For more information see e.g the Pasquill
scheme (http://www.webmet.com/met_monitoring/64.html)
An important factor to be taken into account in selecting the upwind sampling locations for determining
the upwind concentration are interferences through other emission sources releasing bioaerosols of a
composition similar to that of the plant under study. Such interferences may result from bioaerosol
contributions of adjacent plants or the resuspension of previously deposited bioaerosols originating
from the plant of interest. As a result of such interferences the upwind concentration may be higher
than that at an interference-free sampling location. A differentiation of the microorganisms will
normally allow plant emissions to be distinguished from those of other emission sources.
For the above reasons, the following requirements are to be observed for the determination of the
upwind concentration:
a) Upwind (Luv) and downwind (Lee) concentration measurements shall be performed
simultaneously to determine the plant impact.
b) The upwind side shall be confirmed by measuring the wind direction throughout the measurement
period.
c) Upwind concentrations (Luv) should normally be measured at a distance of 250 m from the
geometric centroid of the source or source system of the plant in the direction counter to the
prevailing wind direction. Built-up areas or the specific topography may make it necessary to select
a smaller distance in justified exceptional cases. The selected distance is to be documented in the
measurement report along with supporting information. The same applies to any further emission
sources to the extent they can be identified.
NOTE As the land use can have an influence on the type and concentration of the microorganisms
encountered, the terrain at the selected upwind sampling locations should be similar to that at the site boundaries
(e.g. agricultural land, asphalted surface) in order to obtain representative background levels.
d) Further requirements concerning the arrangement of the upwind sampling location are laid down
in 11.3 as well as in Figure 1 and Figure 2.
e) Care should be taken to ensure that there are no cold air drainage flows between the plant and the
upwind sampling locations at the time of the measurement.
f) For reasons of data comparability, the measurement method used for quantifying the upwind
concentration shall be identical with that used for the downwind ambient air measurements. This
applies to both sampling (e.g. filtration method, impingement) and analysis.
10 Measurement strategy for plume measurements
10.1 General
Bioaerosol concentrations are known to vary considerably over time which is partly due to the inherent
variability when collecting samples with short sampling duration and partly due to true temporal
fluctuation, caused mainly by horizontal wind direction fluctuations, in exposure levels. This needs to
be taken into account when determining the mean impact of a plant.
A fan-like arrangement of sampling points aims to ensure that the sampling points are affected by the
plume because the real position of the plume varies by time and spatial extent. It is recognized,
however, that a fan-like sampling arrangement will not always be feasible and alternative
arrangements, such as a central traverse model may be applicable.
There is a risk of a difference between the results obtained with the central traverse sampling
arrangement and the fan-like sampling arrangement, depending on the spatial fluctuation of the plume.
10.2 Principle and objective of plume measurements
In plume measurements, the location of the measurement area is determined by the prevailing mean
wind direction. Measurements are performed downwind of the plant or source using a fan-like
sampling arrangement (see Figure 1).
Typical objectives of plume measurements are (see also Clause 4):
a) determination of spatial concentration distribution and/or the additional impact contributed by the
plant;
b) determination of ambient air bioaerosol concentration under unfavourable dispersion conditions
(e.g. cold air drainage);
c) determination of the mean impact range (see Annex B).
10.3 Contextual information
Before proceeding to the ambient air measurements, all available information of relevance to the
measurement strategy shall be obtained and considered in the measurement plan (example see
Annex D). Such information includes, for instance:
a) Source characterization:
Prior to performing the ambient air measurements, the pl
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