All posts by smahoschadmin

Should I Test My Home For EMFs (electromagnetic fields)?

ELF and EMF radiation at high levels have been shown to have negative health impacts. They can lower melatonin levels and there are also studies of milk production from cows that show their production decreases with Elf/Emf radiation (they sometimes graze under high tension powerlines).

A T.V. in the old days had an emf burst when you turned it on (remotes are great for keeping your distance) but now the readings are just a few milligauss (mg) depending on your TV. Still….keep yourself and kids back from the large sources like microwaves and electrical transformers.

Powerlines and larger sources of EMF: For long term constant exposure, Sweden has a 1mg (milligauss) limit and Florida, USA has a 250mg limit. High tension power lines are usually around 345,000 watts and produce measureable emf’s which drop as you move out from under the power lines or away from a 25kva or 50kva transformer (commonly on the CFE street poles in San Miguel).

Do you need to test? If you suspect a source such as a transformer on a pole outside your house then yes, I recommend testing. Or download an app for android or I phones. They don’t compare well in my tests to my F.W Bell meter but at least they can indicate if a field exists then you can test further with better equipment. SMA Home inspections uses an F.W. Bell ELF meter that measures the emf in milligauss (mg). (Note: 1 microtesla=10 milligauss). Measurements of appliances up close can give 20-60 mg and a microwave might be around 200-300 mg. The field drops rapidly as you move the meter away hence distance from the emf source will lower exposure for those concerned.

Is Radon a Problem in Mexico?

Recent discussions on the SMA Civil List about radon in the water reminded me that I wanted to post a little information and resources to more information about Radon here. I may start testing for radon within the next year as an “add on” service like the mold testing and inspections we do but so far the data doesn’t show a high risk in most mexican cities (see below).

Radon is being studied in Mexico and there are also global radon maps. Here is a link to a study:
There is a table with Radon levels of nearby cities of Celaya, Guanajuato, Queretaro etc. Divide by 37 to get the pCi/l so you can compare to the EPA recommendations here: Anything below 2.3 pCi/l is considered low risk but above 4.0 pCi/L you should consider mitigation to reduce the levels.

Note that geology changes and radon levels will defer from area to area. So if anyone has information on radon testing in San Miguel de Allende I would appreciate the link. There is also a study of radon in water at a thermal water spa if you want to google that.

Solving Hard Water Ecologically

TAC or “template assisted crystillaztion” is a newer technology finally gaining ground in the United States and I am looking for a source here in Mexico. It does not need to be backwashed and does not put salt into the sewer like the traditional softeners with brine tanks. So help me out if you find a source for TAC. TAC originated in Germany and was tested by Arizona State University in April 2011. The link below is to a .pdf file with a power point presentation of the testing structure and the results of several technologies. TAC came out on top for the lowest scale deposits on a hot water heater coil. Also below a link to a nice explanation of TAC.

Hot water heaters pay the biggest price from scale build up but we all know it is the clogged shower heads and the plugged up low pressure on the sink faucets that annoy us the most.

Low Cost Alternatives: take off any shower heads and aerators (those little screens screwed into the spout of your faucets) and soak in vinegar overnight. Scrub with a brush and replace. You can tie a plastic bag with vinegar on the faucets and the shower heads you cannot remove. Wrap a rubber band around the bag to seal it and get some of the fixture soaking in the vinegar. Remove the next day (or wait 2 or more days if you can) and scrub with a plastic brush.

Here is a link about TAC, a nice explanation:
Here is the study from ASU:

10 Things You Should Know About Mold

I just finished another mold test in La Lejona II here in San Miguel de Allende, Gto. Mexico. Many sources of mold were found and I advised the owners to spend the test money on controlling moisture in their house but when you are suffering from allergy symptoms sometimes you just need to know. So we tested for stachybotrys (black mold) and aspergillus and penecillum and the tests were negative for both. That did not mean they did not have mold, they did. It just means the worst ones for your health were not present. So that allowed them to focus on the moisture control tasks ahead and continue their search for other possible allergins. The EPA has been weakened by the Trump administration but I am glad they got to do some research on mold and provide us with information on their website (link below). Also, do your own mold clean up with these 2 links from the CDC and EPA

Ten Things You Should Know about Mold (from the Environmental Protection Agency)

  1. Potential health effects and symptoms associated with mold exposures include allergic reactions, asthma and other respiratory complaints.
  2. There is no practical way to eliminate all mold and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.
    If mold is a problem in your home or school, you must clean up the mold and eliminate sources of moisture.
  3. Fix the source of the water problem or leak to prevent mold growth.
  4. Reduce indoor humidity (to 30-60%) to decrease mold growth by:
    • Venting bathrooms, dryers and other moisture-generating sources to the outside
    • Using air conditioners and de-humidifiers
    • Increasing ventilation
    • Using exhaust fans whenever cooking, dishwashing and cleaning
  5. Clean and dry any damp or wet building materials and furnishings within 24-48 hours to prevent mold growth.
  6. Clean mold off hard surfaces with water and detergent, and dry completely. Absorbent materials such as ceiling tiles, that are moldy, may need to be replaced.
  7. Prevent condensation: Reduce the potential for condensation on cold surfaces (i.e., windows, piping, exterior walls, roof, or floors) by adding insulation.
  8. In areas where there is a perpetual moisture problem, do not install carpeting (i.e., by drinking fountains, by classroom sinks, or on concrete floors with leaks or frequent condensation).
  9. Molds can be found almost anywhere; they can grow on virtually any substance, providing moisture is present.
  10. There are molds that can grow on wood, paper, carpet, and foods.

Does magnetic treatment of hard water reduce scale deposits?

There is no consistent independent testing that supports the claim. There are many studies that show that magnets and magnetic fields have no effect and the few that show a reduction in scale build-up are often flawed or biased or have specific industrial applications. For the average home owner I think you should spend your money on a traditional water softener with a brine tank. The dissolved sodium chloride is minor. The excerpt below is from this article here.

Consumer Reports magazine (Denver 1996) tested a $535 magnetic water treatment device from Descal-A-Matic Corporation. Two electric water heaters were installed in the home of one of the Consumer Reports staffers. The hard water (200 ppm) entering one of the heaters was first passed through the magnetic treatment device. The second water heater received untreated water. The water heaters were cut open after more than two years and after more than 10,000 gallons of water were heated by each heater. The tanks were found to contain the same quantity and texture of scale. Consumer Reports concluded that the Descal-A-Matic unit was ineffective.

Mold: Bed Bath Recalls UGG Comforters

Bed Bath and Beyond has recalled around 175,000 comforters because of mold contamination. This time of year, many of us here in San Miguel de Allende are huddled around space heaters (see previous blogs on air quality issues) and dive into bed early to keep warm. If you brought a comforter from the U.S. and wonder if it safe you can go here for more information on the recall. I am not an alarmist. If you keep your comforter clean and dry there should not be a problem with mold. But if you have one of these comforters I suggest getting the refund and start with a mold-free comforter.

I received this notice from IAQA, my Indoor Air Quality Association membership:

“Bed Bath & Beyond Recalls Nearly 200K Comforters Over Mold”
Good Housekeeping
Bed Bath & Beyond is recalling nearly 200,000 UGG comforters sold in stores nationwide and online over concerns about mold, and warns anyone who bought the products should immediately stop using them.”

SMA Home Inspections does basic mold testing and can make suggestions on how to minimize mold growth in you home.

Is It Safe To Heat Your Home With The Gas Oven?

If you research this you will find the answer to be a resounding NO…!!! THEY COULD BE WRONG and here is why. If it is dangerous and if you will get carbon monoxide (the most often cited danger) then you better forget cooking the turkey for thanksgiving. Why is turning on your oven for 3-5 hours to cook a turkey okay and turning on your empty oven for an hour or two to warm up your kitchen (and dining and living room in today’s open design homes) not okay?

First of all, many vent less gas log sets found all over the world and very common here in San Miguel de Allende  burn less efficient on purpose. Some have a yellow flame like a real fire which may indicate lower temperatures and incomplete combustion. Your oven should have a blue flame which means it is more efficient than many of the alternative space heaters using propane or natural gas including vent less gas log sets. Ovens are built to bake bread, cook a turkey and keep food warm for hours and hours at a time. They are usually not vented, poorly insulated and let all of the heat into the room which makes for a decent source of heat. If there is carbon monoxide it should be well within standard limits, otherwise they could not sell you the oven for cooking.

The only real danger is if the oven flame somehow goes out while the valve/knob is left on and at the same time the safety malfunctions and sends unburned gas into the house. Does this happen when you are cooking a turkey? Note: newer gas log sets have an oxygen sensor that turns off the gas if the room becomes depleted of oxygen below a certain safe level. Does your gas heater have this safety feature? Your oven does not have this feature so be careful using you oven as a space heater.

Yes it is true, an oven was not made for space heating. But the blue flame of my oven tells me it is burning more efficiently than my gas fireplace log set. After an hour or so my eyes are burning from the fireplace log set. This is not the case with the oven. Distribution is a problem equal to both heaters. So I don’t recommend using an oven to heat a large area. But if your oven is safe to cook a turkey for a few hours, then it is safe to turn on with or without a turkey to take the cold edge off the kitchen in the early morning (never leave an unvented gas heater on while you sleep). Am I missing something here?

Are Propane Gas Log Heaters Safe?

Propane gas log sets come in a variety of styles and sizes. They are generally safe to operate but only for an hour or less at a time. The Canadian study here  found that 1 in 5 homes using vent less heaters like the gas log sets found in many San Miguel homes had unsafe levels of carbon monoxide (CO) and oxides of nitrogen dioxide (NO2).  Your log set is probably located in a fireplace nicho, but don’t let that fool you. Look inside and up and you most likely will find there is no vent or chimney. You have a vent less heater and you need to be careful.

Personally, I find them unhealthy and I hope to see more homes with direct vent heaters, radiant in-floor heat and other safer and healthier heaters installed in San Miguel homes.  Gas log sets are designed to burn less efficiently with a yellow flame (like a real fire) instead of the more efficient blue flame. Fortunately, the doors and windows in many San Miguel homes leak air and this allows for contaminated air to exit and cleaner air to enter. But of course this lowers the efficiency of your heaters.

What are the warning signs:

  • yellow/orange flame instead of blue/white indicate less complete combustion
  • strong smell of combustion
  • physical symptoms of incomplete combustion (eyes burning, headaches, nausea, dizziness etc)

What can you do ?

  • install carbon monoxide sensors that sound an alarm
  • purchase good quality gas heaters,
  • service the gas heater every year in the fall and insure you have blue flames indicating more complete combustion of the propane gas
  • do not use your heaters continuously, use them for an hour at most and supplement with electric heaters, warm clothes, electric blankets etc.
  • open you doors and window when the outside temperature is higher than in your house. Close up in the late afternoon when you feel the cool air outside.

Filling Your Propane Tank

A civil list report in January of 2017 alleges that a gas company (go to the sma civil list on yahoo for more info) used a magnate to lower the fill percentage on the tank gauge thus justifying a larger amount of fill and a higher bill.  (using a magnate does not change the printout, where does the extra gas go ???)….. So now as a consumer I am concerned that the receipt I get is not from my fill but from another more empty tank or near empty tank fill. They can reprint these receipts. I believe there has to be 2 components to the “scam”.

I see no date stamp or anything on my receipt that identifies it as mine. There is a “Numero de Nota” example #13638. There may be the possibility to imput this type of information on the 3 lines below the amount that show asteriks ***** . There is hand written date and a total showing my VIP discount. My total was 96.8 liters at $7.19 per liter for a Total of $695.99. The handwritten total was $595 for my VIP discount ($100mp which is too much and also raised my suspicious nature) which Imperial gas will give you even though it is Providencia Gas that is the official VIP gas company. I got mixed up and called the wrong company. Please report any “hanky panky” with caution but as a group, if we stop using one of the suppliers, I think this will have an impact on the company and make them clean up the problem whether internal or external. So again, be sure, be cautious.

My suggestions (if you cannot climb on your roof have a trusted gardner or cleaning person help out).

  • check (or have someone check) the gauge just before filling and give the gauge and tank a good thump to see if it is stuck. This is important even if the fake or recopying of receipts from other tank fills is happening. Please send us an email if the gauge moves after thumping so I can confirm that this can occur.  Write on the receipt your prefill and postfill gauge  percentage so you establish a relationship between percentages and liters to fill. Please note this is going to be different depending on temperature, time of year/angle of sun on the tank etc. Not an exact science. Aaaah such is life…!!
  • Ask when you call and before they fill if the receipt they will print is readable (I have gotten unreadable very faint receipts). Then ask them to wait to print until you are standing there and can watch the receipt print (can there be a discrepancy between the meter and what you get ?? possibly yes but we are trying to tighten up our process best we can). Before you let one of them go up to the roof, ask them to wait to reset the meter/printer mechanism until you return. If you have two people then you can send someone up while you watch the setting of the meter.  I know….what a hassle !!
  • Escort the filler to the top. I have arrived up top late only to smell a lot of gas and when I asked what the hell is going on they said they were just checking the valve. Although this doesn’t put money in their pocket directly, filling a tank that is more empty helps the company and also shortens the time it takes them to empty the truck tank (perhaps there is incentive from the company ??). We as consumers should understand how it all works.
  • If the filler guy goes to the roof through the house and you only have one person, then after they reach the roof, lock them out of the house and apologize that you have to do this and will come back to escort them through the house. This is not being paranoid, it is common sense. If you have a fill valve on the street you can supervise it all from there.
  • Go down and supervise the meter reset, the printout and pay the bill. Go escort the roof top person down but ask for an “porcentaje exacto”. Write both pre and post fill percentages on your bill and over time you can get an idea of how many liters you will need. By buying a set amount each time you can also calculate how many percentage points this $500 or $1,000 pesos represents on your gauge (at that time of year or temperature).  Good luck and be vigilant.????

Do You Have Dangerous Mold ?

The answer is….”you probably do not have so called toxic mold”. The conditions needed for black mold (stachybotrys is one of the most toxic) are significant and are often not present here in San Miguel.  Black mold is black/green in color, often slimy and found in association with cellulose (drywall paper, cardboard, wood window sills etc). But if you are allergic, immune deficient or highly sensitive then of course any mold can cause health problems.

We are still looking for a reputable Mexican lab to do mold testing but until then, we have the ability to do quick on-site testing which is an important first step. We can determine if you have one of the 3 most toxic molds (Aspergillus, Penicillium,Stachybotrys). We can follow up with U.S. based lab testing but that takes time.  You can order your own kit here and save our fees but it can take a few weeks to get the kit. Why not have an informed professional inspect for mold and perhaps save the kit fee altogether? In most cases we can eliminate the need for lab testing and also suggest simple remediation steps (better ventilation, stop the moisture source etc).


Since the most dangerous black mold (stachybotrys) is very rare it is better to remove doubt from a home owner’s (present or future) mind with a quick test.  Recently, I received a call from a potential buyer about a moldy lower level laundry/maids room with poor ventilation. Based on their description, I doubt very much that toxic molds were involved but perhaps the doubt was a factor in their decision to let their offer expire. I did not get the chance to inspect and alleviate or corroborate their concerns.

We have the training manuals, documentation and information on the microbiology, the remediation schemes and most important the respirator and clothing specifications for the  most extreme cases (involving large infected areas or sophisticated ventilation system contamination).  We will share this information along with ozone “shock treatment” alternatives with anyone interested.

Note: as with all inspections, we can suggest and recommend some basic remediation steps, professional remediation contractors, ozonator options and other information but do not perform these services ourselves because of obvious conflict of interest concerns.