I have done a lot of stupid things in my life, but as a father now of three children, I now take time to consider my actions the health and well being of my kids. The case in point is the renovation of the house we just bought. For the past twenty-odd years, I have been living hand to mouth, rented cheap, ‘funky’ places with character, but have lived relatively well. So when it came time to buy my first house, naturally it was a fixer upper.  Built in 1893 that has seen its share of renovations and alterations over the past 118 years that has included plastering the walls and coating the floors and walls with layers of paint. Paint that I am pretty sure has lead in it – and plaster that can often contain asbestos.

24 Rue Brook. La Maison de M. Gendron

Our house: Built in 1896, renovated dozens of times, including the 1950’s – when lead in paints was all too common.

Of course, to save a few bucks, I started the renovation as soon as we moved in – and to contain the dust and mess, split the house into two zones, front and rear. Our entire family of 5 now live, cook, eat and sleep in the rear of the house – the kitchen – while I have worked on gutting the front rooms – living and dining areas. After ripping out about 4 layers of wall and floor coverings – amounting two a large construction dumpster worth of material or approximately 5 tons – I am now looking at the original surfaces. The dust has come and gone – with regular sweeping and thorough vacuuming occurring at  intervals along the way. But a little cross-contamination is inevitable. Foot-traffic between spaces, doors opening and closing, cracks, strong wind events – the dust ends up pretty much everywhere to a greater or lesser degree. No big deal right? It’s just ‘construction dust’.

Well, that construction dust – I am learning – may have the potential to fundamentally and irreversibly  impair the neuro-cognitive function of my kids. I have lived in California – where lead disclosure forms are a part of every residential sale and lease, and placards on public buildings stating the presence of neurotoxins is a standard, mandated practice. One looks at the things, and rents or enters the buildings anyways. What else are you supposed to do? Well, the state of California (reference to legislation) takes lead VERY seriously, and as I am now learning – for good reason. My parents never took it seriously but they have ignorance as an alibi, and we should know better by now, which is why I am writing this article!

From having done renovations before – there is a certain palette of colours that are ‘of a time’ (mustard yellow, pale green) – and that you just know are very likely to be lead-based paints. When heat is applied by friction (sanding), it can tend to ‘melt’ (forming a shiny film that clogs sandpapers), has a nasty burned ‘metallic’ smell, and when submitted to a lab for analysis – your hunches are confirmed. In some states sanding lead-based paint is actually illegal – and when my neighbour – an engineer with significant toxic remediation experience under his belt discovered how I had planned to refinish my partially-lead-painted 2.5″ thick pine floors – he was more than a little concerned, but unfortunately kept it to himself – nobody likes confrontation.

After experimenting with a few chemical strippers, the prospect of weeks of being on my knees scraping paint had me considering just sanding the bloody stuff off – albeit in a very ‘controlled’ way. The floors I sanded that had no paint on them kicked up sawdust everywhere and so to contain the dust I rigged up a 6 amp shop-vac with a fine filter bag and a HEPA cartridge, and tried sanding inside a specially constructed 4’x4′ ‘sanding tent’ to limit the spread. That worked pretty well –  I kept a stainless steel table in the room as a control surface that I could get an anecdotal sense of dust accumulation on before and after the work. But the sanding tent was a PITA (pain in the ass) – and so I went to Home Depot and rented an industrial drum sander. These usually have a bag for collecting sawdust,  but I removed the bag and hooked it up to my trusty HEPA shop-vac instead and tested a patch. It looked like this method produced even less dust than my tent method – it was almost like pushing around a big vaccuum cleaner that happened to vaccuum up an eigth of an inch of flooring – no fuss, no muss!

After sanding the floors in this way, my neighbour dropped by, and followed up with a very detailed email about why what I had done was not sitting well with him. His concern was at first met with my typical defensiveness, but as I started to do more and more research, my opinion of him as an ‘anal engineer’ or ‘nosy neighbour’ started to be tempered by the sobering research that I started to uncover. Of his recommendations was to get a proper lab analysis done. Before I started any of this work, and when I first discovered the floor paint, I purchased a first alert home test kit from Walmart (hydrochloric acid) – but the results were hard to interpret. The test substance was to turn brown to indicate lead, but mine turned yellow. How much lead was yellow – compared with brown? I did a bunch of samples, and none of them could be said to be conclusive – so I assumed the lead contained had to be minimal, and proceeded to remove surfaces – ignorance is bliss, if only partial!

So who knows how to get a ‘proper lab analysis’ done anyways? There are any number of ‘experts’ out there that will be more than happy to come and empty your wallet to provide such testing, when in fact all that is required is a special kind of wet wipe called a ‘ghost wipe‘ that doesn’t interfere in the destructive testing of the sample, a ziploc bag – and a local environmental lab that specializes in soil air and water testing. The lab nearest me was Paracel, and they even gave me and my son a tour to see how the tests are performed (photo of collected samples below). One does not need to hire an expert! Anyone can take a careful sample for analysis by marking out one square foot, and wiping up all of the dust on that patch, or by carefully scraping up a decent sized chip with the paint in question. For testing for asbestos, I just took a chunk of the plaster. Each sample cost me $24.00 – but gave me extremely accurate results that allowed me to smarten up and to reconsider just how ‘careful’ my methods were.


My neighbour went on to say that the spaces need to have an ‘airtight’ separation, that the P100 3M mask I was wearing needed to sit on a clean shaven face, that I needed to be wearing a complete dust-suit – and that all filter cartridges, and that vacuum bags and waste needed to be disposed of as hazardous waste.

That seemed a little bit over the top for me. After all – my dad used to make us scrape lead-based paints as kids in the process of restoring an old steamboat that we lived on – I don’t even remember wearing a mask. Our dad was the cavalier yahoo at the other end of the spectrum – this is a generation of folks that drank oil and breathed asbestos to prove some kind of machismo – so any thought of protecting oneself from exposure to toxins was paramount to being a sissy. I must admit – I inherited a bit of that bravado but there must be some explanation for my completely burned-out thyroid, inability to motivate myself to do work that I know needs to be done, and occasional trouble focusing on complex mental operations required for my job as an intern architect, more on this in a minute…

I just watched Homo Toxicus – a Canadian documentary film about the body burden of toxic chemicals. The kids in the far North suffer the worst because their diet is high in fatty meats, the top of the food chain is of course the highest in bio-accumulated toxins, from metals to PCBs, pesticides, even DDT!

What scientists are learning, is that the typical symptoms are chronic, recurring ear-infections, hearing loss (auditory nerve), and a general restlessness, hyperactivity, or ADHD. Even otherwise smart kids, that just have an impossibly difficult time staying focused, or following specific instructions. My own kids manifest this, but I always just assumed it was because they were related to me – a hopeless daydreamer – scatterbrained, etc. Could it have been those cheap, ‘funky’ rental properties we had lived in? As a child, my mother declined to give me ritalin – but I was considered hyperactive (before ADHD was coined) and I know firsthand that I was extremely disruptive. I always had just assumed that was my ‘personality’. It turns out lead destroys myelin – the sheath that surrounds and protects the nervous system, and it impacts the brain first, and can lead to numbness and loss of sensation in the arms and hands, and ultimately something called ‘claudation’ – as in Roman Emperor Claudius, who had a terrible limp and stutter – lead aqueduct liners anyone? This is a problem people have known about for centuries – so why did we put it in paint? See the video below:


John Warner: Intellectual Ecology from Bioneers on Vimeo.

Now I am beginning to think there may be something else at play (hypochondria?). From a recent decreased strength in my hands, to my ineffective thyroid, to high blood pressure (150/96 for a 40 yr. old) to insomnia (I am writing this at 4am), to trouble with multiple tasks (such as orienting myself to North when I am driving South on an iphone map, or misplacing items, or remembering shopping list items or quantities of multiples, or having a helluva time converting US and CAD dollar values in exchange transactions)… one could say this happens to everyone – but I am sure I was much sharper in my twenties, and I am suspicious that age alone cannot be to blame.

The most telling aspect of Homo Toxicus was their determination of toxicity in the human body. As Paracelsus famously said – “poison is the dose.” I had assumed if I decreased the amount of dust I created (which is mostly wood sawdust and only a tiny fraction paint, and then a fraction of that as lead), and that over 90% of that got picked up by my 99% efficient HEPA vaccuum  – that I would not be spreading ‘much’ lead around the house at all by sanding in what I thought was a well-controlled way. Hardly scientific – but as Enrico Fermi would have done, I just tried to look at the proportions in the larger picture, if 3% of the paint contained lead, and less than that is contained in the mixture of wood sawdust, say less than 1%, and then 90% of that got picked up by the vacuum and 99% of what the vacuum picked up was fully captured, then what I was left with was really ‘not much lead dust’.

Well, ‘not much’ is all it takes to seriously impair a child’s cognitive development. The analogy used in Homo Toxicus was a few grains of salt in an olympic swimming pool. Really – that little? Health Canada has set some standards with respect to what they consider an acceptable level of lead in dust on various surfaces in a daycare – one of the most stringent environments because of the potential danger:

  • less than 40µg/sf – allowable on a floor… single surface wipe
  • 250µg/sf  – on window sills or exterior sills
  • 400µg/sf – for a window trough – basically the deep groove that a window seats itself in, or slides back and forth on

The workers at my daycare have recently reported, that my daughter Beatrice, now 2 yrs old, has been ‘acting up’ – is more aggressive with the other kids, has regressed (is wetting herself where she was 100% potty trained), and has been falling over more frequently. Now I am completely alarmed, and patiently waiting the 4 days for my samples to return. Time for a second blood serum test! The kids have always been kept out of the ‘construction zone’ – but these results will determine whether we should even be in the house at all. I am starting to shift along the spectrum with what I am learning now. I took a few samples – a swiped ‘ghost wipe’ atop the refrigerator in our ‘safe’ zone and an office desk in the ‘medium safe’ zone, and a sample of the actual lead paint, and then a sample of the plaster for asbestos for good measure (photos). The total for 4 samples was $105.00

Well, the results of the surface samplings are in:

  • 20µg/sf – on the refrigerator (before any cleanup had been done, the fridge was the least often cleaned surface in our safe zone)
  • 193µg/sf  – on an uncleaned work table in the work zone
  • 34,200µg/g – in the paint chip, or roughly 3% of the volume of the paint was lead.
  • No asbestos in the plaster (I had not realized it until now, but many plasters DO contain asbestos!)

Of course – once I understood that I had created airborne lead dust (which is dense and so settles on every horizontal surface after 1 day or so), and that the levels in the work zone were well beyond what is acceptable in a daycare, I created a complete airseal between the work zone and our living space, and began a thorough cleaning of all books, toys and pretty much every surface that collected dust after I had begun work. The hard work paid off, as a followup sample showed that the lead in airborn dust having settled on the fridge after 3 weeks was now down to 2 micrograms per square foot. But I had worried that in my sloppiness, I might have exposed the kids. Fortunately, for our 2 year old, I had obtained a baseline level after we first moved in – because I was concerned even back then, which showed negative exposure. On followup – her second and most recent blood serum result still showed no exposure – thankfully. Her recent behaviour has just been a function of personality, and we really haven’t noticed the changes that the daycare has. She is a well coordinated little smartypants at home. According to Dr. Andrew Heyman – an expert in the field of lead poisoning, blood serum levels are only accurate from the first to third month of initial exposure, before the body begins to store the lead in other places – treating it much the way it treats calcium, it ultimately gets stored in the bones (lead lines can be seen in xrays, and in cases of extreme exposure, in the gumline) – but that initial exposure to the nervous system is what can do the most damage.

My 2 year old’s blood serum levels before and after major disruption of the lead paint showed less than <0.01µMOL/L – or exposure-negative. To make sense of these values – here is a comparative table from:


Industry Mean Blood Lead Levels^
umol/L# ug/dL#
Population reference level* <0.50 <10.36
Battery Repair 2.9 60
Engine Reconditioning 3.3 68
Motor Vehicle Assembly 4.6 95
Plastic Formulation 3.1 64
Pottery 3.6 75
Printing 3.2 66
Radiator Repair 4.3 89
Solder Manufacture 3.3 68
Soldering 3.0 62

The range of levels of above can be misleading though. According to the WHO, there is NO SAFE LEVEL of lead exposure, but ironically, every individual on this planet can be shown to have lead in their system – in trace amounts at or below the reference level shown in red. The higher the amount however, the more pronounced the symptoms and effects, and the higher the exposure level, the greater the necessity of the removal of the individual from the contaminated environment and the necessity for treatment by chelation (pronounced kee-lation).

All in all, knowing what I know now, would I undertake to remove lead paint, by scraping or careful HEPA-sanding, when equipped with an appropriate respirator? NO!!! Not at all in a space where I am living at the time. That was a really dumb idea, and if I can convince anyone else reading this NOT TO DISTURB LEAD PAINT IN AN INHABITED LIVING SPACE, I would hope they would take my advice and the trouble I have taken to write and study all of this. I can only be thankful that dumb luck more than my presumptive ‘careful methods’  prevented my kids from exposure. With what I understand now, it simply isn’t worth the risk. By the way – all of the reading I did on the internet before did not arm me with sufficient information to make an informed decision on how to proceed, only my own experience and testing revealed that what I had undertaken was wrong-headed, and so I hope others can learn from my mistake.

I have yet to explore the linkages of lead to my own health issues, but blood serum testing will probably not reveal much as all traces generally disappear from the blood after 30 days or so. Only intravenous EDTA (a chelating agent) challenge and subsequent urine testing can accurately reveal the body’s long term lead burden, I’ll mention what – if anything – turns up when I have that done. If nothing, well, then I may just be a hypochondriac, but for my kid’s sake, I would sooner be safe than sorry. In the interim, I am starting a course of treatment with a medical-grade infrared sauna* – as advised by my own Doctor, and MD sister.

Further references:

John Warner, Intellectual Ecology – on why we even make toxic substances
*Sauna as treatment modality: http://www.saunaray.com/32p_lead.htm
Resources to add later:
CAT scan of lead damaged brain, citing reduced volume,
Report on violence in society, crime, the criminal brain and lead, irreversible damage due to lead
Andy Thomson is contributing author to GCM news.  As an Ottawa-based intern architect, currently working in the field of green architecture, he will continue to provide timely information on matters pertaining to the built environment in the context of human and environmental health. His website can be found at www.earthstream.ca