PM2.5 exposure due to MSWI in Hämeenkyrö

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Scope
PM2.5 exposure due to MSWI in Hämeenkyrö describes additional primary PM2.5 exposure due to the Hämeenkyrö MSWI plant emissions. Annual average exposure concentration in Hämeenkyrö.

Description

Human exposure to fine particles
Fine particles are particles smaller than 2.5 µm of aerodynamic diameter. They are often produced by combustion processes, and they enter human breathing zone both outdoors and indoors. Fine particles are considered the most dangerous air pollution to health. The average exposure to fine particles in Finland is in the order of 10 µg/m3 (one millionth of a gram in one cubic metre of air). A large fraction of fine particle exposure comes as long-range transport from hundreds or even thousands of kilometres away. The most important emission sources in Finland are domestic combustion and traffic.

Describes the variables affecting the personal exposure to MSWI-produced PM2.5. Certain concentration assumed and dose calculated from it.

Data needed to evaluate the personal exposure

  1. Data needed to model the PM2.5 concentration distribution around the MSWI:
    1. The emission produced by MSWI
    2. Stack height and location of MSWI in relation to municipality
    3. Meteorological data: average (e.g. daily) temperatures, wind speeds and directions, solar radiation etc.
    4. Geographical data: vegetation, elevations, town build, lakes etc.
    5. ...
  2. Data needed to convert exposure to dose:
    1. inhalable fraction of PM2.5
    2. concentration of PM2.5 around the person in the locations the person moves in
    3. time spent in different locations
    4. breathing rate of the person
    5. weight of the person
    6. ...

References:

  • Atmospheric dispersion model of FMI.

Definition

Formula

D = IR*P*RF*ET*EF*ED / (BW*AT) where
  • D = dose (mg/kg.day)
  • IR = inhalation rate (m3/h)
  • P = particle concentration in air (mg/m3)
  • RF = respirable fraction of particles (dimensioless)
  • ET = exposure time (hours/day)
  • EF = exposure frequency (days/year)
  • ED = exposure duration (years)
  • BW = body weight (kg)
  • AT = averaging time (days) [1]

For dose over a lifetime the formula can be simplified to D = (IR)(P)(RF)/BW B⊙

  1. Schwela D, Morawska L, Kotzias D (Eds.) 2002. Guidelines for concentration and exposure-response measurement of fine and ultra fine particulate matter for use in epidemiological studies. WHO and JRC Expert Task Force meeting, Ispra, Italy, November 2002.


Assumptions:

  • IR = 13 m3/d
  • P = the background concentration, as the emission caused by the MSWI is distributed wide and thus diluted to negligible, thus 7 mikrog/m3/d = 0,007 mg/m3/d
  • RF = 0,6
  • BW = 70 kg

HOWEVER, in most dose-response studies and health effect evaluations the dose = the exposure or even the concentration in air.

Data

0.02 µg/m3

Unit

µg/m3

Result

Dispute:

  • 0.0008 µg/m3 (based on formula)
  • 0.02 µg/m3 (based on data)