California Homes Dusted With Corrosive Ash and Heavy Metals From Wildfires
by John Laumer, Philadelphia on 12. 6.07
There's no great mystery as to why lead and arsenic have been found in such great abundance amongst the ashes spread by California wildfires. Until just a few years ago, pressure treated wood sold for use in decks, railings, fences, wooden playground structures, and foundation sills was highly impregnated with "CCA" - the common term for a wicked brew of Chrome, Copper, and Arsenic salts. If large volumes of CCA-treated wood burned up, it easily accounts for much of the culturally introduced arsenic amongst the ashes.
Ash from wildfires in Southern California's residential neighborhoods poses a serious threat to people and ecosystems because it is extremely caustic and contains high levels of arsenic, lead and other toxic metals, according to a study by federal geologists released Tuesday.U.S. Geological Survey scientists warned that rainstorms, which are forecast for the region beginning Friday, are likely to wash the dangerous substances into waterways, polluting streams and threatening wildlife.
Some ash collected in residential areas after the October fires registered a pH of 12.7, a level more caustic than ammonia and nearly as caustic as lye.
Metals, particularly arsenic, were found in such high concentrations in the ash that they would violate federal standards for cleaning up hazardous waste sites. Metals could have come from treated wood in decks, old lead-based paint, plumbing solder and other household substances.
What about the lead you ask? Vinyl products spec'd to perform in electrical applications like junction boxes may contain large amounts of lead stabilizer.
More importantly, you have your vinyl garden hoses, the nice Chinese-made toys we've all been hearing about from the budget deprived Consumer Products Safety Commission, and miles of plastic fencing, all of which may potentially have included large amounts of lead compound as a "stabilizer." These too went up in flames. And then, as the LA Times points out, there is the matter of lead-based paint on older structures.
Odd, though, that no media stories we've seen or heard got at the fact the lead is commonly added to plastic in China. It's one thing to test the surface of an object to decide if its safe for kids to play with. Quite another to think of the consequences of fire with such products.
Regardless of the lead's origin, is the ash fall a significant source of exposure for children? Is waiting for the rain really a way to mitigate that exposure? This is sounding more ground-zero like than it should. Does Cal EPA have an opinion about whether the heavy metal exposure is a serious concern or not?
Next in line: marine filter feeders. Abalone anyone?
As a matter of public safety, we wonder of contemplated revisions to building codes will take this after-effect into consideration?
Points of clarification: Chinese vinyl products commonly have lead added, whereas vinyl products made elsewhere tend not to have it, with the possible exception of electrical fixtures.
We don't know where all that ghastly looking white vinyl fencing and decking one now sees in the suburbs was made, or what the stabilizers generally are.
Finally, vinyl siding generally uses titanium dioxide as a stabilizer - not lead.
Via::Los Angeles Times, "Wildfires leave caustic ash, study finds" Image credit::Ken Hively / Los Angeles Times
Ugh. Right in my area. I've been saying since the fires that we really need to look at how we build in this area. Lead and arsenic really weren't on my mind; more to do with minimizing damage to homes so fewer need to be rebuilt, and more use of native plants. Since it seems we're likely to have these fires rather regularly, taking steps to cope with the results seems sensible.
People shouldn't be building homes out of wood in forest fire prone areas. My house is made of autoclaved areated concrete, my workshop-storage room and well-building of brick and stone. I had a fire sweep onto my forested countryside finca here in central Spain four years ago and a lot of plants, trees and wooden outdoor furniture burned, but my buildings suffered absolutely no damage (except for the plastic rain gutters which warped and melted from the heat). I had put my car in the workshop area when the fire hit and since it was inside, it suffered absolutely no damage. Everything outside and next to the buildings burned, but the buildings themselves and everything inside were perfectly fine. Luckily, my house and workshop partially acted as firebreaks preventing the fire from spreading to the other side of my finca. As a matter of fact, that forest fire stopped on my finca. If people decide to build in areas that are prone to fires, they should not build out of wood. Masonry is what they should use. If people want to build in areas prone to flooding, they should not build out of wood. Again, masonry is the best choice. If people want to build in an area prone to tornados, wood is not a good idea. Again, masonry is a better option. Wood homes have their place, but in most places - especially places where natural disasters tend to occur - wood is not a good idea, if you want your house and possessions to survive that is.
Houston, we've got a problem! Masonry buidings, as strong as they are, are not suitble in residential construction in earthquake-prone areas - unless you spend the money to heavily reinforce them. Labor is extensive and as we know, US labor costs will blow that budget fast. In Mexico, for example, labor is cheap so you see more concrete and CMU buildings + their safety codes aren't too strict (to say the least!).
The recent major fires in SoCal are quite unusual - 2 major fires within 3yr period. Santa Ana conditions will never go away so fire-hazards won't either. Cost effective construction to minimize destruction is tough. To impose rules for the non-use of non-hazordous materials in and around the house will be next to impossible to impose, let alone monitor.
Sadly, I see no other changes coming out of this fire except further "recommendations" by the industry. It won't be until people feel a direct impact from the regular ash-"fallouts" (sickness, loss of tourism, excessive decay, etc. linked to the bad-ash) when significant changes in implementation and oversight will happen.
'Houston, we've got a problem! Masonry buidings, as strong as they are, are not suitble in residential construction in earthquake-prone areas - unless you spend the money to heavily reinforce them.'
---It is true that traditional masonry construction does not hold up well to earthquake forces. In this respect, traditional wooden homes do much better at surviving earthquakes. Having said that, my home is made of masonry. The building envelope is made out of autoclaved aerated concrete. The building system comes from a company called Ytong. And my home IS earthquake proof. Because the envelope system does enable the insertion of reinforced concrete in specific crucial points of the envelope to ensure that the structure remains in tact after an earthquake. Traditional masonry construction can not handle earthquakes well. Much (maybe most) MODERN masorny construction can handle earthquakes just fine.
'Labor is expensive and as we know, US labor costs will blow that budget fast.'
---The extra cost for my house of 'reinforcing' was nil - since the reinforcement of the AAC is done with normal concrete and rebar, which is cheaper than the AAC. There was some extra labor work required but little - I should know since I built my home by myself with my own two hands.
Having said that, the reason people in the US build almost exclusively out of wood is because it is so CHEAP. In most of Europe people refuse to build out of wood because of its many drawbacks. Homes in Europe, especially southern Europe, are built almost exclusively out of masonry - even though as in the US it is cheaper to build a wooden house than a masonry house. People in the US are willing to take bigger risks with their homes.
'In Mexico, for example, labor is cheap so you see more concrete and CMU buildings + their safety codes aren't too strict (to say the least!).'
---Last time I checked many, possibly most, construction workers in the US ARE Mexican or Central American. So construction labor is cheap in the US too.
As for Mexican safety codes, they are probably very strict, as they are here in Spain too. Unfortunately, as in Spain, the fact that safety codes are strict doesn't mean a home will be built to code. And I do agree that it is very likely that many buildings in Mexico probably are not built to code. But having said that, I'd rather have a masonry home not built to code in Mexico than a wood home built to code in the US. Masonry homes simply have less problems than wood homes and require less time, effort and money in terms of maintenance and renovation, and they last a hell of a lot longer.
'The recent major fires in SoCal are quite unusual - 2 major fires within 3yr period. Santa Ana conditions will never go away so fire-hazards won't either. Cost effective construction to minimize destruction is tough.'
---How tough can it be? The US is one of the very richest countries in the world, yet 'poorer' countries throughout southern Europe and the Mediterranean build almost exclusively out of masonry, and I have never once heard a debate in Spain, or any of these other countries, about how we need to switch from masonry to cheaper wooden buildings. What am I missing that you know? And just in case you are wondering, southern Europe also has extensive forest fires each and every summer.
AAC is the only thing a home should be constructed of now and forevermore,the only reason a AAC home cost more (it really dose't) is due to shiping cost here in the western U.S. The closest operating plant is currently in Monterey,Mexico. I am about to change that very soon by reopening a plant in Casa Grande,AZ that use to be called E-CRETE and was poorly operated by a guy that bought it and named it TRUESTONE. AAC when made properly is basiccally a fire proof, mold proof, sound proof, termite proof, vermin proof and higly engery saving green style means of construction. ANYBODY including carpenters can build a home out of AAC. It's very seismic resistant and only needs to be covered with a plaster coat on both the inside and outside to be finished.NO insulation, NO paper and wire, NO scratch or brown coats,and NO drywall except on all other interior walls. America needs to wake up and save it's forestry for better things. The rest of the world has been building out of AAC for well over 60 years, it was invented by germans and you know they know how to engineer things! The National association of home Builders just finished their 2008 show home and it is saving over 60 % in engery cost. I live in So Cal and I would love to save $$ on my sce bill. Soon, very soon I will, by building out of AAC myself. Also the 1st place home in Las Vegas parade of homes this april is made of AAC. Look for E-CRETE to reopen soon ! ! !