One Take #7 - Formaldehyde, Damp, and Mold in English Housing

We dive into a fascinating paper that quantifies respiratory disease burden from formaldehyde, damp and mold in English housing. Using Disability Adjusted Life Years (DALYs) as a metric, researchers reveal the hidden health costs of poor housing conditions while highlighting significant data gaps that could mean we're vastly underestimating the problem.

• Formaldehyde exposure in English homes associated with approximately 4,000 new childhood asthma cases (800 DALYs) in 2019
• Official surveys indicate 4% of English homes have significant damp/mold problems
• Damp and mold exposure linked to 5,000 new asthma cases and 8,500 respiratory infections (2,800 DALYs)
• Alternative data suggests up to 27% of homes might have damp issues, potentially making the health burden 3-8 times higher
• Clear pattern of inequality shows low-income households and ethnic minorities bear greater burden
• Research highlights urgent need for better national surveillance of indoor environments
• Paper provides a framework for understanding housing as a quantifiable public health and equity issue

The Burden of Respiratory Disease from Formaldehyde, Damp
and Mould in English Housing

Thanks a million to our sponsors, SafeTraces, and InBiot who make this podcast possible.

Chapters

• 0:00 Introduction to "One Take"
• 0:39 Study on Respiratory Disease Burden
• 1:43 Formaldehyde Health Impacts
• 4:19 Damp and Mold Findings
• 6:02 Housing Inequality Issues
• 7:15 Key Takeaways and Significance

Transcript

Speaker 1: 0:14

welcome back to air quality matters and one take one take, my take on a paper or report on air quality, ventilation and the built environment. One take in that it's well one take and tries to summarise for you a specific perspective on something interesting in well, usually 10 minutes or less, because who has the time to read all these amazing documents? Right? This week we're diving into an interesting paper that feels especially timely. It's titled the Burden of Respiratory Disease from Formaldehyde, damp and Mold in English Housing, and it's authored by Sierra Clark and a team from the UK Health Security Agency. Now we talk a lot about damp and mold, especially with the recent focus on housing conditions and the introduction of Arabs law here in the UK in September this year. We know instinctively that these things are bad for us. But what this paper tries to do is move beyond the instinct. It tries to put hard population level numbers on the problem. It asks a simple but incredibly difficult question Can we actually count the cost of poor indoor air quality in terms of people's health? And that's a question well worth trying to answer. So the researchers set out to quantify what's called the burden of disease. This is a public health concept that doesn't just count cases. It tries to measure the impact of a health problem. They use a metric called DALYs, which stands for Disability Adjusted Life Years. You can think of one DALY as one year lost to healthy life. It's a powerful way to measure the real human cost of a condition or risk.

Speaker 1: 1:56

They focused on two key respiratory diseases asthma and lower respiratory infections and looked at two culprits in our homes formaldehyde and the duo of damp and mould. Now, they didn't go out to measure every home in England that would be impossible, frankly. Instead, they acted as data detectives. For formaldehyde, they pulled together the data from 11 different monitoring studies done in english homes over the years to create a picture of what typical exposure is like. For damp and mold, they used a huge and well-established data set, the english housing survey, which gives a professional surveyor's assessment of housing conditions across the country. They then took this exposure data and combined it with the epidemiological evidence, that is, large-scale studies that have already established this risk link the relationship between being exposed to these things and the likelihood of getting sick. This allowed them to calculate something called the Population Attributable Fraction, or PAF, and that's a key idea here. The PAF basically answers the question. If we could wave a magic wand and eliminate a specific risk factor, like all the significant damp and mould in England, what percentage of disease like childhood asthma asthma would disappear along with it? So what did they find? Let's take them one by one.

Speaker 1: 3:31

For formaldehyde, in 2019, they estimated that the exposure in English homes was associated with approximately 4,000 new cases of childhood asthma. Cases of childhood asthma that translated to around 800 disability-adjusted life years lost, and this is a really crucial point of nuance. The authors are very clear that this number is highly sensitive. It all depends on where you set the safe threshold. The science isn't totally settled on the exact concentration where formaldehyde starts to cause problems. So, depending on what threshold you pick, that number of 800 DALYs could swing dramatically up or down. The uncertainty is a theme we'll come back to Now.

Speaker 1: 4:19

For damp and mould, using the English Housing Survey data, which suggested around 4% you heard me correctly row 4 of homes have a notable problem. The researchers found that in 2019, this exposure was associated with about 5,000 new cases of asthma and a striking 8,500 new lower respiratory infections, across both children and adults. In total, this amounts to roughly 2,800 dalis, or 2,800 years of healthy life lost in a single year. But here's where the paper delivers probably its most powerful and, frankly, most concerning insight. The whole calculation is based on that English housing survey figure of 4% of homes having a problem. But what if this number was wrong? The paper highlights that other data sources, particularly those based on what people self-report, paint a very different picture. One survey suggests that as many as 27% of homes have damp or mould. If that's true, the authors note that the real burden of disease could be three to eight times higher than their primary estimate. Think about that for a moment. The difference between a survey classifying a home as having a significant problem and a person living in that home saying yes, I have a damp problem is massive. It means the true health costs could be substantially underestimated and the burden isn't shared equally.

Speaker 1: 5:59

The paper calculated separate pas for different groups and found a clear pattern of inequality, a theme we've covered a lot on the podcast. Households in the lowest income quantile and those where the head of the household identified as black, asian or another minority ethnicity had a significantly higher population attributable fraction. This isn't because these groups are biologically more susceptible. It's because the data shows that they are more likely to be living in damp, poor quality housing that causes the exposure in the first place. It's a stark reminder that poor housing is a social justice issue.

Speaker 1: 6:42

So what do we take away from all of this? Why does the paper matter? First, it gives us numbers. They may be uncertain, but they're not zero. We're talking about thousands of children and adults getting sick every year and thousands of years of healthy life being lost because of a condition of our homes. Even the most conservative estimates presented here are significant and should be a real cause of concern for public health officials and policymakers. Second, and I think this is the most important message, it highlights a massive data gap at the heart of our understanding of this problem.

Speaker 1: 7:20

The huge discrepancy between different data sources on the prevalence of something like damp and mould tells us that how we measure the problem fundamentally changes our perception of its scale. It makes a powerful case for the need for better, more systemic national surveillance of indoor environments. Without good data, we're effectively flying blind. This paper doesn't necessarily give us easy answers. In fact, it raises more difficult questions about how we define and measure risk in our homes than presents any kind of a solution.

Speaker 1: 7:57

But it's incredibly valuable because it gives us a robust framework for understanding the consequences. It helps to shift the conversation from a vague damp is bad for you to a much more powerful statement Damp, in English. Housing could be responsible for thousands of respiratory infections and a significant burden of asthma, particularly among the most vulnerable, and that's a language that should drive investment policy and a greater urgency to ensure that every home is a healthy home. This paper proves with data that the quality of our housing isn't just a matter of comfort or aesthetics. It's a fundamental and quantifiable issue of public health and equity. Thanks for listening. This has been the One Take podcast, and thanks a million for our sponsors, safe Traces, who, without them, this podcast wouldn't be possible. See you next week.