CLAIH assessment: Difference between revisions

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Climate change, air quality and housing – future challenges to public health (CLAIH)

CLAIH analytica model

This assessment calls for new participants to work on this important topic.

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Scope

Purpose

The purpose of the assessment is to evaluate cost-effectiveness of different measures to reduce green house gas emissions from household heating in Finland when costs from indirect health impacts of the measures are also taken into consideration.

More specifically:

What would be the health impacts of different options for heating system and energy efficiency renovations in detached houses constructed in 1960-1970?

From the society's point of view, what would be the most cost-effective (combinations of) measures to reduce green house gas emissions from this type of houses?

Is there a conflict between the cost-effectiveness of different measures when either a society or a house owner is considered?

Boundaries

Population: Finland
Assessment time frame: 2010-2030
Evaluated activity: heat consumption in detached houses
Evaluated exposures:
- Fine particles (PM2.5)
- Indoor Radon
- Indoor dampness and mold
Evaluated health impacts:
- Mortality (and morbidity?) due to long term exposure to PM2.5
- Lung cancer mortality due to indoor radon
- Asthma due to indoor mold and dampness
Other evaluated emissions: CO2
Evaluated costs for a house owner:
- Cost of heating system renovation (investment, interest)
- Cost of energy efficiency renovations (investment, interest)
- Cost of heat consumption (heat energy, maintenance)
Evaluated costs for society:
- Costs for house owner (excluding taxes)
- Cost of health impacts
- Cost of CO2 emissions

Specific decisions evaluated

New heating system
- Light oil
- Pellet
- District heating
- Direct electricity + air heat pump
- Ground source heat pump (GSHP)

Form of district heat production (evaluated only in terms of PM2.5 health impacts)
- BAU
- Small scale power plant (<5 MW), wood
- Small scale power plant (<5 MW), oil

Energy efficiency renovation
- BAU (no renovation)
- New windows
  - (U factor 1 W/m2K, air leak factor reduced by 20% to 0.24/h)
- New windows + increased insulation for walls and roof
  - Wall U factor 0.17 W/m2K
  - Roof U factor 0.09 W/m2K
  - Air leak factor reduced by 50% to 0.16/h
- New windows + increased insulation for walls and roof + heat recovery ventilation
  - Heat recovery efficiency 60%

Emissions, health impacts, and costs are evaluated for:

An average detached house constructed in 1960-1970
- The house is in need of basic renovations unrelated to energy efficiency improvements
  - New heating system (excluding heat distribution system)
  - New windows
  - Wall renovation
All houses houses similar to the one described above in the Finnish building stock?
- All changed at the start of the assessment follow-up period?
- Changed gradually throughout the assessment follow-up period?

Intended users

Ministry of Employment and the Economy
Ministry of Social Affairs and Health
Ministry of the Environment
Any interested party

Participants

FMI
University of Oulu
THL: Virpi Kollanus, Pauliina, Marko, Mikko Pohjola, Jouni

Anyone interested

Answer

Results

The objective of the preliminary assessment has been to find out the current level of health impacts related to residential heating and indoor air exposures. The future results (year 2030) have been calculated assuming that things in housing stay pretty much the same as they are now. However, population aging is taken into account.

The preliminary results are based on the following assumptions:

Building stock:

Annual building stock loss is 0.3%. Only buildings older than 50 years are pulled down.
Annual new building stock construction is determined based on the annual building stock loss (0.3%) and annual increase in the residential surface area per person (0.7%)
All new buildings are current standard in energy efficiency.
Fraction of heating systems in new buildings is the same as in the buildings constructed between 2000-2010.
No heating system/energy efficiency renovations are done in the current building stock.
Energy efficiency of buildings constructed at different decades is based on the building restrictions at the construction time.

Energy production/consumption:

District heat production:
- 75% in large CHP plants, 25% in small scale heat production plants
- Fraction of used fuels is based on the year 2008.
- These are assumed to stay the same in the future.
Electricity production (fuel fractions) is based on the year 2008. This is assumed to stay the same in the future.
Only primary heating systems in the residential buildings are included in the assessment.
Fraction of the combustion techniques used in the domestic wood heating is based on fractions used for primary wood heating in KOPRA-project.
Temperature increase due to climate change is not taken into account.

PM2.5 exposure:

Only emissions to outdoor air are included in the assessment.
PM2.5 emission intake fraction for domestic combustion is based on the PILTTI-project.
PM2.5 emission intake fraction for large and small power plants are based on KOPRA-project.
Exposure-response function (RR) for PM2.5 exposure and natural mortality is based on the Tuomisto et al. 2008 expert eliciation study (0.97% (90% Cl 0.02-4.54) per 1 µg/m3 increase in PM2.5.
Exposure-response function (AR) for PM2.5 exposure and new cases of chronic bronchitis (age group >27) is 0.0000533 (95% Cl 0.0000017-0.000113) per 1 µg/m3
Exposure-response function (AR) for PM2.5 exposure and restricted activity days (RADs) (age group 15-64) is 0.902 (95% Cl 0.792, 1.013) per 10 µg/m3

Mold and dampness exposure:

Prevalence of mold and dampness exposure in Finnish residences is 15% This is assumed to stay the same in the future.
Exposure-response function for mold and dampness exposure and current asthma is all age groups is 1.56 (1.30–1.86) (Odds ratios for asthma in homes with vs. without visible dampness and/or mold or mold odor)
Asthma prevalence in Finnish population is 8% (assumed to be the same in all age groups)

Radon exposure:

Average radon concentration in Finnish residences is 120 Bq/m3. This is assumed to stay the same in the future.
Exposure-response function (RR) for radon exposure in home and lung cancer mortality is 1.16 (95 % CI 1.05 - 1.31) per 100 Bq/m3.

Population:

Assessment takes into account population aging
Baseline risk of natural mortality and lung cancer mortality is assumed to stay on the year 2008 level.

Results:

Total heat purchase of residential buildings by heating type, kWh/a

Heating type	2010	2030
District	1.84G	1.99G
Light oil	1.53G	1.38G
Wood	1.02G	1.03G
Electricity	1.83G	1.98G
Geothermal	0.35G	0.54G
Other	0.78G	0.92G

Total PM2.5 emission from residential building heat production, t/a

PM2.5 source	2010	2030
Domestic combustion	6000	5880
Small power plants (<50 MW)	290	310
Large power plant	820	890

Average population exposure to PM2.5 due to residential heat production, µg/m3

PM2.5 source	2010	2030
Domestic combustion	0.53	0.53
Small power plants (<50 MW)	0.005	0.005
Large power plant	0.01	0.01

Annual health impact of PM2.5 exposure from residential building heating. DALY: disability adjusted loss of life years.

Health endpoint	2010	2030
Attributable deaths (all natural)	283	373
DALY: mortality	3177	3583
Attributable new chronic bronchitis cases	107	101
DALY: new chronic bronchitis cases	129	121
Attributable restricted activity days (RAD)	166100	133500
DALY: RAD	45	36

Annual health impact of exposure to indoor mold and dampness. DALY: disability adjusted loss of life years.

Health endpoint	2010	2030
Attributable cases: asthma	28090	27260
DALY: asthma	1657	1608

Annual health impact of exposure to indoor radon. DALY: disability adjusted loss of life years.

Health endpoint	2010	2030
Attributable lung cancer deaths	381	440
DALY: lung cancer mortality	5782	5936

Things to discuss in the meeting:

Mold and dampness

Relevance of the asthma prevalence assumption
Relevance of the exposure-response function for mold and dampness exposure and asthma
Other possible health endpoints for mold and dampness exposure
Relevance of the used mold and dampness exposure indicator
Factors related to mold and dampness exposure and health effects
Important things to consider when modelling changes in building stock and the effect these changes have on the mold and dampness exposure and their health effects

PM

Updates for PM emission factors?
Updates for fractions of domestic wood burning devices?
Health endpoints included. Options:
- Natural mortality (PM2.5, long-term exposure)
- Cardiovascular mortality (PM2.5, long-term exposure)
- Lung cancer (PM2.5, long-term exposure)
- New chronic bronchitis cases (PM2.5, long-term exposure)
- Restricted activity days (PM2.5, short-term exposure)
- Work loss days (PM2.5, short-term exposure)
- Minor restricted activity days (PM2.5, short-term exposure)
- Lower respiratory symptoms (PM10, short-term exposure)
- Cardiovascular hospital admissions (PM10, short-term exposure)
- Respiratory hospital admissions (PM10, short-term exposure)
- Medication usage by people with asthma (PM10, short-term exposure)
Should secondary PM2.5 be included in the assessment?
- Possibilities for exposure modelling (intake fractions are only for primary PM2.5)
Should PM10 be included in the assesment?
- Possibilities for exposure modelling
PM exposure assessment: outdoor air concentrations vs. personal exposure approach

Heat

Heat exposure impact assessment is a separate assessment.
Building stock development does affect heat exposure, but it would be very dificult to evaluate health impacts from this.
However, the effects of the building energy efficiency solutions on indoor temperatures can, perhaps, be analysed in some other qualitative or quantitative terms.

General issues

Assessment focus, specific questions asked, issues included
As of now, possible decisions on the following issues are to be assessed:
- Heating options for new residential buildings
- Heating system renovations in old building stock
- Energy efficiency in new building stock
- Energy efficiency renovations as part of general renovations in old building stock
  - Improved wall insulation
  - Heat recovery from air exchange
  - Improved window insulation
- Air filtering in residential buildings
- Form of district heat production (more small scale production?)
- Fuel options for district heat production

Main objective is to answer: what would be to most cost-effective policy options for the society to reduce CO2 emissions from residential heating when the cost from indirect health impacts is taken into consideration?

Conclusions

Rationale

Plan for uncertainty calculations

The final endpoint of the Claih model is Cost share (or total cost, which is the same with cost factors summed up). The health cost part is the heavy part of the model. Thus, if the heavy chain that ends to Total cost of lost life years can be removed and calculated outside Analytica, then all other parts can be calculated there. The idea is that Analytica calculations are converted by MDArrayToTable into a 2D table with Run as one index. This is exported to a file and then imported to R-tools as a static input.

In Analytica, a new node Cost share w/o health is needed: it calculates everything ecxept health, and is then exported to Opasnet. The final cost calculations and VOI analysis is done in Opasnet.

To calculate health impacts, the following nodes must be recoded in R and computed there:

YLL total
YLL, specified
- Mortality, specified
  - Population in time, average for time step *
    - Population in time child *
      - Birth rate
- Age-adjusted life expectancy
  - Population in time, beginning of time step *
- Age weight
- Life years in time
- PV of a life year
Year help
Value of a life year
Present value
VOI (this is a function)

* These three nodes have the most complex code.

Also, these input nodes must be calculated in Analytica, converted, and exported to R-tools:

Mortality risk scenarios
Population data

The downside of this plan is that it may take up to two weeks of working time to convert the Analytica code to R. This may only be worth it, because ICT is to be converted to R anyway, and making this part now would have immediate utility for Bioher and Claih.

Decisions to be evaluated

Figure: CLAIH assessment overview

Society:

Fuel for district heat production (natural gas, coal, wood, peat, oil, geothermal heat)
Form of district heat production (should there be more small scale district heat production?)
Subsidies for household heating system/energy efficiency renovations
Demands/subsidies for new building stock heating systems/energy efficiency
Demands/subsidies for building air filters

Citizen:

Household heating system renovations
Building energy efficiency renovations

Building stock development

Figure: Building stock development modelling

Building heat consumption

Figure: Building heat consumption modelling

Unit heat consumption of buildings in Finland

Emissions

Exposure and exposure-response functions

PM2.5

Figure: Modelling of indoor air PM2.5 concentrations from domestic wood combustion

Outdoor air concentration

PM2.5 concentration in Finland

Indoor air concentration

Personal exposure

Exposure to PM2.5 in Finland

ERFs

Indoor dampness and mold

Indoor radon

Heat

Health impacts

Figure: Health impact modelling

Health impact indicators

Calculated for all exposures:

Attributable mortality and morbidity
Loss of disability adjusted life years (DALY)
- Years of life lost due to mortality (YLL)
- Years of life lost due to morbidity (YLD)
Loss of life-expectancy

Background information needs

Costs

Citizen:

Heat system/energy efficiency renovation investment
Cost from household heating
- Prices of fuels in heat production

Society

Costs from healt impacts

Costs from CO2 emissions
Costs to citizens

Analyses

Cost-effictiveness analysis
Cost-benefit analysis
Value-of-information analysis

@@ Line 74: / Line 74: @@
 '''Emissions, health impacts, and costs are evaluated for:'''
-*One, average detached house
+*An average detached house constructed in 1960-1970
-**Construction year: 1960-1980
+**The house is in need of basic renovations unrelated to energy efficiency improvements
-**In need of basic renovations unrelated to energy efficiency improvements
 ***New heating system (excluding heat distribution system)
 ***New windows