This value set includes codes based on the following rules:

• Include these codes as defined in http://loinc.org

  Code	Display
  20053-5	Atmospheric pressure mm[Hg]
  76268-2	Pressure.ambient Room
  60832-3	Room temperature Cel;[degF]
  65643-9	Relative humidity (%)

• Include these codes as defined in http://hl7.eu/fhir/ig/gk/CodeSystem/gatekeeper

  Code	Display	Definition
  pm10-conc	PM 10 particle mass concentration	Particulate Matter 10 (Particulate matter which passes through a sizeselective inlet with a 50% efficiency cut-off at 10 μm aerodynamic diameter) particle mass concentration
  pm2.5-conc	PM 2.5 particle mass concentration	Particulate Matter 2.5 (Particulate matter which passes through a sizeselective inlet with a 50% efficiency cut-off at 2.5 μm aerodynamic diameter) particle mass concentration
  pm4-conc	PM 4 particle mass concentration	Particulate Matter 4 (Particulate matter which passes through a sizeselective inlet with a 50% efficiency cut-off at 4 μm aerodynamic diameter) particle mass concentration
  pm1-conc	PM 1 particle mass concentration	Particulate Matter 1 (Particulate matter which passes through a sizeselective inlet with a 50% efficiency cut-off at 1 μm aerodynamic diameter) particle mass concentration
  co-conc	Carbon Monoxide concentration (ppm)	Carbon Monoxide concentration (ppm)
  co2-conc	Carbon Dioxide concentration (ppm)	Carbon Dioxide concentration (ppm)
  voc-conc	Volatile Organic Compounds concentration (ppm)	Volatile Organic Compounds concentration (ppm)