1

Indoor air quality monitoring in 650 single family dwellings in the French speaking part of Switzerland

Joëlle Goyette Pernot*, Corinne Hager Jörin, Hélène Niculita Hirzel et Vincent Perret

(*) Federal office of public health radon delegate for French speaking part of Switzerland

ROOMS 2016 – Concarneau – France – 06-07.10.2016

Aims of the research

• To measure various parameters including radon,

VOC, and bio-contaminants in the air of single

family dwellings on a voluntary basis of the

occupants

• To make a survey of building and human factors

for each dwelling

• To evaluate indoor air quality over a large

sample of new and refurbished energy-efficient

single-family dwellings located in the 6 French

cantons of Switzerland

2

Context of the study – The Swiss

Energy strategy 2050

• To lower the final energy consumption by 54%

and electricity by 18% per person and per year

by 2050 compared to that of 2000

• To cover the current share of nuclear power

(40%) with renewable energy

• To reduce GHG emissions by 75% and to

produce less than 1,5 ton of CO2 per person per

year 3

Improving energy efficiency of

buildings …

• … is one of the main levers of this strategy!

• Buildings are consuming 50% of primary energy

and the building sector is responsible for more

than 50% of the CO2 equivalent emissions

• Around 1.6 millions of buildings and 83% of them

need to be energy refurbished

• Barely 1% of them have already been refurbished!

4

Performed measurements from

2013 to 2016

5

Housings Number Relative frequency

New Minergie build. 182 28

Renovated Minergie 35 5

Traditionaly renovated build. 433 67

Total 650 100

Housings VOC Lingette Sensor Sample

New Minergie build. 45 39 43 8

Renovated Minergie 9 8 7 4

Renovated build. 115 110 114 52

Total 169 157 164 64

650

What means Minergie label?

6

• A label for new and renovated buildings

• Mutually supported by the Swiss Confederation, the

cantons and the Chambers of Commerce and Industry

• Energy value consumption limits are based on building

category and are more stringent than the legal

requirements

• Label required for public buildings in several cantons

(exemplary of the State)

• Main objective: better user comfort

• Minergie-Eco requires reduction of pollutant emissions

from building materials and limitation of ionizing and non-

ionizing radiation by ensuring [Rn] < 100 Bq.m-3 of air

and [COV tot] < 750 mg.m-3

Should Minergie standard better

act facing the radon and IAQ?

7

In the absence of adequate air renewal in the building …

Minergie buildings generlly imply a stronger air tighness

[Rn] inside Minergie buildings should be very low as well as other

indoor air quality parameters

Radon is usually entering building because of leaks in contact with ground surface

Minergie standards require an automatic ventilation system

… radon tends to increase in confined spaces

Research question

?

Questionnaire0. Identification

1. Construction considerations

2. Inhabitants description

3. Organisation in the house

4. Building materials

5. Building technic

6. Equipment and use

7. Damages

8. Life custom

9. Comfort

10. Health

11. Energy consumption

616

Clear differentiation of

behaviour of different

types of buildings

10

p<0.001

A strong geological footprint

11

Construction considerations

12

Terr

ain

nat

ure

l dan

s la

cav

e

Pu

its

can

adie

n e

t vi

de

san

itai

re

Infl

uen

ce d

u t

ype

de

str

uct

ure

se

lon

la z

on

e d

e r

isq

ue

rad

on

p=0.01

p<0.001

Basement effect

13

A. Sous sol standard

B. Sous sol semi excavé

C. Rez adossé au terrain

D. Pas de sous sol30% 19% 35% 15%

(p<0.001)

CMV – benefit effect?

14

Type de bat<300

Bq/m3

≥300 Bq/m3

Proportion≥300 Bq/m3 par type

Minergie avec VMC

190 7 4%

Minergie sans VMC

4 0 0%

PB avec VMC

12 2 14%

PB sans VMC

321 55 15%

• No significant effect of the CMV Same proportion of buildings ≥ 300 Bq/m3

of air with or without CMV• All buildings ≥ 1000 Bq/m3 of air do not have CMV 18 cases with a mean

radon concentration of 2031 Bq/m3 of air (median of 1636 Bq/m3)• The only building equipped with a CMV do use it only seldom and is having a

radon concentration of 1594 Bq/m3 of air

Pas de VMC Avec VMC

Impact of energy renovation

15

p<0.001

p=0.007

p<0.001

And what about after

energy renovation?

16

[Rn] after = 1.18 X [Rn] beforeon average for 60 buildings

p=0.24p=0.23[Rn] after global renovation= 1.42 X [Rn] before

(54 buildings)

General sanitary state

regarding chemical factors

• TotVOC between 25 and 2292 μg/m3

• 14 samples (8%) over the FOPH

recommendation (1000 μg/m3)

• 21 samples (12%) exceed the

threshold fixed by Minergie Eco (750

μg/m3)

Generally combined levels of VOC

are under control in the great majority of

houses assessed during the

measurement campaign

17

0

10

20

30

40

50

60

70

<300ug/m3 300-1000ug/m3 1000-3000ug/m3

Nbd'habitations

COVtotaux,MvsPB

M PB

Selon seuils de l’agence fédérale allemande pour l’environnement

169

What is the influence of

the type of building?

18

M PB

n 54 115

Moyenne (mg/m3) 319 415

Médiane (mg/m3) 167 259

écart type (mg/m3) 452 448

Median values of Tot VOC about 1.5X superiors in buildings PB compared to Minergie ones

p<0.01

BTEX – volatile

organic hydrocarbons

• Main external source: traffic

• Other local sources : incense, cigarette, solvent for painting…

19

p=0.002 p < 0.001 p < 0.001

Mean concentrations about 2 to 3 times superiors with an internal parking in the building compared to building without an inside garage

What’s about

formaldehyde?• Ubiquities indoor pollutant coming from

different sources like resin, glue,

domestic products, etc)

• Formaldehyde concentration measured

between 0.5 and 50 μg/m3. No sample

over the FOPH recommendation (125

μg/m3)

• Median concentration of14 μg/m3 tvery

similar of the median value of 19.6

μg/m3 obtained by the Observatoire

français de la qualité de l’air intérieure

(OQAI) during the measurement

campaign of 2007

20

Fungal contamination

Samples at the source• Only 32% of the samples coming from

Minergie buildings and 56% of those coming

from renovated buildings were positives and

provide conditions for the moulds to grow

• Inhabitants have difficulties to distinguish

moulds from salpeter or yeast, particularly

for people living in Minergie buildings

• Bathroom and basement can be

contaminated whatever the type of building

• Bedroom contamination depends and

increases with building age

21

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

20

00

-20

15

19

75

-19

99

19

50

-19

74

avan

t 1

95

0

What do we find in dust?

24

0%

5%

10%

15%

20%

25%

30%

20

00

-20

15

19

75

-19

99

19

50

-19

74

avan

t 1

95

00%

5%

10%

15%

20%

25%

30%

20

00

-20

15

19

75

-19

99

19

50

-19

74

avan

t 1

95

0

Résultats des prélèvements d’été Résultats des prélèvements automne

Cross analysis

• Correlation coefficient equal to 0.20 between VOC tot and radon

concentration (p=0.01) If there is radon accumulation, it is also

possible to note VOC accumulation too!

• Negative correlation between Cladosporium CFU number and the

number of VOC More Cladosporium we have, less VOC diversity

we found (r=-0.33 , p<0.001) because more we ventilate, more

Cladosporium is entering and more VOC are going out

• Negative correlation between radon and Cladosporium CFU letting

assume external source of Cladosporium

• Positive correlation between Cladosporium CFU and propionaldehyde

concentration (r=0.30 , p<0.001). Cladosporium could emit this VOC

in the indoor environment when it is present possible marker

25

Conclusive remarks

• Energy renovation not taking into account indoor air renewal is a major

source of sanitary deterioration of indoor environment as well as a mid

or long-term building degradation

• Challenge for the future. The radon legal regulation revision in

Switzerland as well as the lowering of the tolerate value will compel to

better take into account radon in building in the close future

• Improving radon sanitary conditions should also contribute to enhance

and to improve global indoor air quality

• Real necessity to make building professional awarded by the radon

problematic and globally IAQ but risk management needs also to pass

through an informed public

27

Partenaires et sponsors

• Partenaires académiques et institutionnels

• Partenaires économiques et sponsors

28

Thank you for your attention