Monetary Costs of Office Air Contaminants

This article is based on a paper presented at the joint 45th AIVC conference and ASHRAE 2025 IEQ conference “IEQ 2025: Rising to New Challenges: Connecting IEQ to a Sustainable Future”, held on 24–26 September 2025 in Montreal, Canada.

Key words: Indoor Air Quality; DALY; Office Buildings; Cost-benefit.

Offices expose adult populations to airborne contaminants for several hours each working day. To support practical cost–benefit thinking for indoor air quality (IAQ), we combine (i) office concentration evidence from global sampling studies, (ii) contaminant-specific harm expressed in Disability-Adjusted Life Years (DALYs), and (iii) published monetary values per averted DALY for very-high Human Development Index settings. The output is an annual monetary burden per person for priority contaminants. Results highlight particulate matter (PM) as the dominant cost driver, suggesting a clear focus for cost-effective IAQ interventions in offices.

Building decisions often compare intervention costs (filtration, source control, ventilation strategies) against energy or maintenance budgets, while health impacts remain difficult to express on the same scale. DALYs provide a single harm metric that combines years of life lost and years lived with disability. By assigning a monetary value to an averted DALY, office contaminant exposure can be translated into an annual economic burden that is directly comparable with the cost of control strategies [1]. This does not replace compliance or comfort-based assessments; it provides an additional, health-centred lens for prioritising interventions.

Methods, in brief

We start from a compiled dataset of office contaminant concentrations reported in the literature [2]. Concentrations are time-weighted to reflect typical office occupancy (about 6–8 hours/day), using an exposure factor of 0.25. For each contaminant (i), harm was calculated (Harmi,DALYs per 100,000 people·year) [1]. To monetise harm (Costi), we sample a cost-per-DALY distribution (HarmCost) representative of very-high Human Development Index (HDI) settings (Table 1) and compute:

Costi = HarmCost · Harmi

Uncertainty in concentrations, harm, and HarmCost is propagated with Monte Carlo sampling; we report medians and uncertainty using geometric standard deviation (GSD).

Key input: cost per DALY averted

Table 1 shows the monetary value per averted DALY adopted (PPP-Int2011$: PPP-adjusted constant 2011 international dollars). We apply the very-high HDI distribution to reflect the predominant evidence of indoor air contaminants base from high-income office studies [3].

Table 1. Cost Per DALY Averted (HarmCost, Units Of PPP-Int2011$/DALY). [3].

Results: which contaminants dominate the monetary burden?

Across the prioritised contaminant set [1], six pollutants (out of 44 considered in this analysis [1]) account for most DALY burden and therefore most monetised costs. Particulate matter is the main driver (≈62% of total costs). Table 2 reports concentration and monetised cost results for these six highest-harm contaminants, ordered by median harm.

Table 2. Time-Adjusted Chronic Inhalation Concentrations, Harm and Monetary Cost of Pre-Prioritised Contaminants. Highest to Lowest Harm Median.

Figure 1 shows the median annual monetary cost per person for the six highest-harm contaminants.

Figure 1. Median monetary cost per person-year for the six highest-harm office contaminants.

How to use the metric for cost-effective IAQ decisions

The monetised burden can be used as a screening benchmark: if an intervention that primarily reduces a given contaminant costs less (per person-year) than the estimated Costi, the measure is plausibly cost-effective on health grounds. Because PM2.5 dominates both health and monetary outcomes [4], strategies that reduce fine particle exposure (e.g., filtration, source control, and preventing outdoor particle ingress) are likely to yield the largest returns. Absolute cost estimates are directly proportional to the ‘cost per DALY averted’ values, so these should be stated clearly.

Limitations

Results depend strongly on (i) representativeness of office concentration datasets, (ii) the harm estimates, and (iii) the chosen monetary valuation of a DALY. Cost-per-DALY estimates vary across valuation methods (willingness to pay, value of statistical life, gross domestic product multipliers) [5] and differences can shift absolute cost estimates by an order of magnitude [1].

Conclusion

DALY-based monetary valuation offers a practical approach to quantify IAQ health costs in offices. PM2.5 dominates impacts, reinforcing prioritisation of interventions. Transparent, standardised DALY monetisation remains essential for robust policy and investment decisions.

Acknowledgements

To a University of Nottingham Faculty of Engineering Research Excellence Scholarship. To the Chartered Institution of Building Services Engineers (CIBSE). To HARMONISE (Autonomous Province of Bolzano/Bozen, Decree No. 4400/2025).

References

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