Health and Fitness – Geeky Girl Engineer

Stair Pulley System

Posted on September 24, 2023 by geek

Surgery for scoliosis was two months ago now, and I am still recovering. My ability to walk is improving slowly as my body adjusts to the new spinal arrangement. I have a limp that is going to take time to fix. I can climb and descend stairs, but I have to hold onto the railing with one hand, and it is really better if my other hand is at least touching the other side. The main part of my house is on the second floor, so I have had to figure out how to get things up and down the stairs if I want to live on my own.

There are a couple of solutions, but I am engineer, so naturally I installed a small pulley system to transport items up and down the stairs. I think it is the most efficient solution. I bought a small pulley with accompany hook and rope, and I installed it on the railing overlooking the stairs. My stairs have a landing at the halfway point where they change directions, so that made the pulley system really easy to install and allow for a straight path for items to ascend and descend.

Note that my cats oversee all operations of the pulley.

Pulley system installed on stair railing

Pulley used

Groceries loaded onto hook to lift to second floor

Groceries pulled to the second floor

Scoliosis 4 Weeks Post Surgery

Posted on August 19, 2023 by geek

Four weeks ago today, I was in the hospital having had surgery to correct my scoliosis the day before. My neurosurgeon said the surgery lasted about six hours, but I was sedated for about 12 hours. They sedated me at about 7:30 a.m., but my neurosurgeon said surgery did not begin until about 9. I woke up after 7 p.m., but my neurosurgeon said surgery ended around 3. I had warned the anesthesiologist before that I was a slow metabolizer. My guess is that they did not give me a reversal, but they just let me sleep after surgery, which was probably a good idea.

I have no idea how many people were actually a part of the surgical team, but I know there were two neurosurgeons to decrease the amount of time I was in surgery. I learned right before surgery, that there was also a surgical neurophysiologist who would be monitoring my nervous system the entire time I was in surgery to make sure the neurosurgeons did not harm my nerves. [A few days after surgery, I told my neurosurgeon that he should have told me about the surgical neurophysiologist months before surgery because knowing someone was there whose entire job was to make sure my nervous system was not damaged made my stress levels go down as that was one of my big concerns. He apologized and said he thought he had.] Then there were who knows how many nurses, the anesthesiologist, the nurse anesthetist, and at some point during surgery, an x-ray technician came in, so they could check their work.

After surgery, I now have a rather renovated, blinged out spine that has been enhanced with two rods (one per side), 26 screws, and (by my count on the x-ray) seven artificial discs. My neurosurgeon swears I will not set off every metal detector I come near. I have not tested this yet. According to the radiology report, my spine has been fused from T7 down to the pelvis, which I think is about half my spine. So yeah, my spine was rather messed up before surgery. Sadly, as best I can tell despite all that metal, my spine does not seem to have bionic abilities.

I spent a week in the hospital. The day after surgery, in the morning I was able to stand, but then I got lightheaded and had to sit back down. Later that afternoon I was able to stand again and sit in a chair a few feet away. I was walking with a walker I think the next day, only a few steps though. After a few days though, I was doing slow laps around the hospital wing with my walker. Once I started getting out of bed, I was given a rather uncomfortable back brace, which would not be so bad except it strangles me when I sit upright.

I have been home for three weeks, and I can’t express how happy I was to get out of the hospital. It took several days before I could sleep in my bed. There were a variety of reasons for that, but for the first couple of days, the couch and ottoman were just more comfortable and easier. Now I have pretty much mastered the log roll to get into and out of bed. I can manage a lot on my own, but I have trouble getting things below waist height. I am not supposed to bend, and my thighs, particularly my left thigh, are so tight, I can’t really squat either. I am actually not in much pain anymore. When I go to bed and lay on my back and thus the incision, then I have some pain as it is still rather sensitive. Most of the problems I have now is that my body got used to my scoliosis and compensated in various ways. Now my body is trying to get used to this new spinal configuration. My left leg is much weaker than the right, and as the scoliosis was to the left, clearly I had been compensating for some time unknowingly. Also when sitting, I keep leaning to the left.

For several years I have had pain in my back near constantly, and x-rays proved that the pain was exactly at the apex of the spinal curve. The good news is that pain is completely gone. Now I just need to regain my strength and flexibility. I have been given strengthening and stretching exercises, which help. At the physical therapist’s advice, I bought a pair of walking sticks, which I use to do laps around the house to increase my strength and endurance. I still get around with a walker though. I don’t need the walker for support. I need it for stability, as I walk rather wobbly currently. Also, when standing from a sitting position, I need something to push off with my arms.

I don’t regret having the surgery. I admit I am somewhat frustrated by how slow my recovery is, but I know that is to be expected. My only regret is how long it took to get an accurate diagnosis, so I could make the decision to have the surgery. I have suffered needlessly for years. I only hope to get back to normal in the coming months and once again have the active lifestyle I used to have.

Scoliosis

Posted on July 20, 2023 by geek

At the age of 49 I was diagnosed with scoliosis. Scoliosis is normally diagnosed far earlier in life. My scoliosis is not some sort of weird adult onset type. In fact my neurosurgeon pointed out evidence on some of my spinal images that showed how long it had been there, but I am getting ahead of myself.

I can remember in junior high when everyone had to go to the gym in shifts, separating the girls and the boys, to be checked for scoliosis. My maternal grandmother had scoliosis, so I was at increased risk, yet it was not caught when I was young. I have never had good posture, but now I look back and wonder if my bad posture was really a symptom. Now, sitting with really bad posture is a mechanism to avoid pain. Basically curving my back puts the spine in an alignment to relieve the pressure, I now realize, based on the x-rays.

I have had back pain for so long that I don’t even know when it started. It has been increasing in pain level and consistency though. I can remember what was my first attack of sciatica and related muscle spasms. It was about twenty years ago, and I was in graduate school. I was having serious nerve pain in the hip area, and I went to the student health center. The physician prescribed a muscle relaxant and pain meds. I went to the bathroom while I waited for the pharmacy to fill the prescription. When I tried to get off the toilet, the muscle spasmed with such intensity, I was not sure when or if I could stand up. I finally did. I didn’t need the pain meds really. I just needed the muscles to stop firing.

Since then, the back pain has gotten worse, and a variety of others issues have come about. Several years back frustrated by the constant back pain, my physician prescribed physical therapy. I needed to build my core muscles I was told. A physical therapist pressed on my back in places trying to get the muscles to release. The muscles generally refused to release, and I give the physical therapist the benefit of the doubt that she never pressed in the correct location to feel my spine in the not correct location.

A couple of years ago, I started having hip pain. My physician sent me to an orthopedic specialist, who ordered x-rays. Sadly the x-rays were aimed at my hips and just out of range of the lumbar region of my spine. Another missed chance to see the scoliosis. The specialist said I had IT band syndrome. Basically I was walking funny because of my back pain and/or sciatica, so that caused the hip pain. I just needed to stretch the IT band, and I would be fine. He said I needed more physical therapy. I declined to go because I had been there, done that.

For years now, I see a dermatologist annually for what she calls “mole patrol” to check for any signs of skin cancer or other issues. She checks my entire body. I give her the benefit of the doubt that they way I lay down on my stomach while she checks my back does not make the spinal deformity obvious. I have had physicians and nurses on countless occasions listening to my lungs with a stethoscope. I get annual physicals. I give them all the benefit of the doubt that they never noticed the spine out of alignment.

Two years ago, as I was once again pressing my hand to the part of my back that always hurts, it dawned on me that my back has a lump of sorts where the pain is. Why it just occurred to me then I have no idea. I am sure it had been there longer. Feeling around my back, and I know something is wrong. Is it my spine I wonder? The lump is such that when I lay on a flat surface, I cannot lay flat. My left side touches the surface when I lay flat, but not the right side. I go in for my annual physical and ask the physician. I hadn’t seen this physician but maybe once before because the physician I normally saw at the same practice had recently moved, and I needed a new physician. The new physician asks if I have scoliosis. I don’t know I say. She has me bend over and check my spine. No, she says, the lump is just soft tissue.

The coincidence of the location of the lump and my pain is too much for me to ignore. I am also slightly concerned that I have soft tissue lump on my back. Is this a giant cyst? I go back to the same practice but see a different physician. I explain the issue. She says, let’s just get an x-ray. The radiology report says “Some height loss at the right aspect of L1 vertebral body. Accompanying approximately 50 degree leftward curvature centered at L1-L2, accompanying advanced multilevel disc height loss, endplate degenerative changes. Mild wedge compression deformity of L1, with mild accompanying increased kyphosis.”

“Some height loss.” Did I mention I used to be 5’7″, but a couple of years ago during a physical they said I was 5’6″. I remember arguing that no, I was 5’7″. It never dawned on either the nurse, doctor, or myself why in my late 40s I had lost an inch.

So yeah, I have scoliosis. That’s the problem. The radiology report was a shock to say the least. My physician sends me to a neurosurgeon. He orders more images, more x-rays, CT scans, and MRIs. The radiology reports all agree on scoliosis, but some say 40 degree curve, and some say 50 degree curve. No matter which, it’s a lot. When I viewed the images with the neurosurgeon I started crying. They say a picture is worth a 1000 words. Seeing an image of my spine was somehow far more emotional, devastating, and hard to handle than reading a very clinical radiology report with lots of words that I had to look up. My neurosurgeon pointed out bone spurs on two vertebrae at the apex of the curve on some of the many images. The bone spurs formed to try to protect the vertebrae from rubbing against its neighbor he says. That’s how we know this scoliosis started a long time ago.

I used use a standing desk at the office. Until several years ago, I used to go for five mile walks. I used to go for 20 mile bike rides. I can’t anymore. I can barely walk more than a couple of blocks before the back pain starts. On my road bike, I have to stop after 15 minutes or so to stretch my back because of the way the road bike forces me to lean over in a manner that stresses my spine. At least my hybrid bike is better because of the way I sit in it. It wasn’t always like this. The back pain used to be on and off. Now it is constant. I used to run. Less than a decade ago, I ran fairly regularly, and in fact I once could run 10 miles. I was never fast, but I had endurance. Knee pain forced me to stop. Now I have to wonder if the knee pain was at least somewhat related to the scoliosis.

I feel like I have been gaslit by the medical community for at least a decade. For as many times as I have complained about back pain, the solution was always to lose weight and build my core muscles. I am overweight, but I eat a healthy diet, and I am very active. I exercise near daily. Elliptical machine, walking, biking, weight and resistance training, rowing machine, etc. At least I used to. There is only so much exercise you can do when the pain is so intense and constant. However, core muscles and weight loss was always the issue I was told. How much stronger did my core have to be before the pain ends? I am not even sure if they believed me when I said I work out every single day. Maybe they did, but they just didn’t care. More to the point, I will also never understand how the one physician could possibly feel the lump on my back and call it soft tissue. How can anyone, especially a physician, feel my spine in a completely incorrect location and not realize it?

My neurosurgeon said that with scoliosis of less than 30 degree, surgery may not be necessary. Mine is severe enough that surgery is really the only option other than “putting out fires” as he says. My quality of life is degrading to such a degree that I decided surgery was my only option. I want to be able to continue to travel. I want to be able to go for long walks or long bike rides again. Surgery is no guarantee that my quality of life will return to what it was a decade ago, but I feel like I have to take the chance.

My neurosurgeon and I discussed the surgery options. I agreed with him that the more invasive surgery is better if only because my spine is not just curved, it is also rotated, which adds more complexity to the surgery. He said there is a less invasive option, which divides the surgery up over two days, but he was worried with the spinal rotation, he still might have to go more invasive for the second surgery day. I agreed it was better to just do everything in one go with the more invasive surgery. Two neurosurgeons working on me at once for a surgery that will probably take six hours.

Surgery is tomorrow, and I am terrified. I am scared of dying. I am scared of becoming paralyzed. I am scared I will still be in constant pain. I am scared of going through all of this, and I can’t resume the life I used to have years ago. I am not afraid of months of physical therapy. I am just scared because there is no guarantees. I can’t do my engineering calculations with safety factors and redundancy to have a high degree of confidence that my design will work. I can only trust in a medical team because almost everything is out of my control. About the only thing I can control is donating two units of blood to myself in the past week and a half because my neurosurgeon said with the more invasive option I might need a transfusion. I donate blood on a regular basis. One unit of blood doesn’t really phase me anymore. Donating a second unit of blood to myself one week after the first, per the schedule given to me by the blood donation service, rather zapped me of my normal energy. I plan to tell my surgeon and anesthesiologist that even if I don’t quite need a transfusion, I would rather like some of my blood back.

I have been preparing for tomorrow for several months now. Pre-operative exam with blood tests and EKG. Autologous blood donation. More blood tests at the hospital. Now I type this blog post to try to sort out my emotions and keep myself calm because I am terrified. I really don’t want to have this surgery, but I don’t want to live the rest of my life with my quality of life rapidly decreasing with constant back and hip pain, sciatica, and who knows what else may start. I have to have faith. Faith in God, and faith in my neurosurgeons, anesthesiologist, nurses, and everyone else to fix me. God, please be with my medical team and make me better.

Risk Reduction Engineering for COVID-19

Posted on August 12, 2020 by geek

In response to some discussions I had seen about the use of HEPA filters to help with the COVID-19 crises, I wrote some thoughts on how effective I thought HEPA might be. Several people on Twitter stated they agreed with my statements. An HVAC technician (@JSTootell) provided some thoughts that I had never even considered such as the energy requirements on the buildings where a HEPA filter is installed as HEPA requires more energy (i.e. electricity) to run than normal HVAC filters. He also said the normal air velocity is super low because if you increase the air velocity and hence get more circulation, people complain about the noise of the air through the vents.

Some others have noted that HEPA filters, on a whole HVAC system or portable units in each room, won’t hurt to which I agree. One said they should be a part of a multiple layer approach to prevent the spread of COVID-19 to which I also agree. In fact, while I did not say it, that is part of my argument, HEPA filters alone will not solve the problem of COVID-19 transmission. I want to take a step back though and discuss this from an engineering perspective.

The basic, general idea in engineering is you find out what your design specifications are, you make some calculations and draw some designs to comply with those specifications based on proven information, you throw in some safety factors, and then you build whatever it is to comply with your design and calculations. If you want to build a bridge, you need to know before hand what are the design specifications. Is it for trains, vehicles (cars and trucks), pedestrians, or something else entirely? How many of the intended type of users will be crossing the bridge daily? What is the span of the bridge? What is the height of the bridge? What type of weather will the bridge will be exposed to? There are far more questions, but that is the general idea. You can’t design a bridge until you know what you are designing.

I currently work in human health risk assessment related to exposure to hazardous chemicals. It is not the same as risk assessment related to exposure to infectious agents, but there are similarities. With hazardous chemicals, the goal is to reduce people’s exposure such that they are not at undue risk to the chemical exposure. You can’t reduce risk to zero; it is simply impossible. With chemicals that cause cancer, generally you are trying to get the risk below one in a million chance of cancer caused by exposure to that chemical. Another part of this is who is at most risk. With chemicals, the people we are generally most concerned with are children or pregnant women as they can be more susceptible to harmful effects than healthy, non-pregnant adults. The risk requirement is one of your design requirements. If a person can be exposed to 100 mg/l per day (via ingestion) or 100 mg/g (via inhalation) of a certain chemical and not be above one in a million risk of cancer, then you have to figure out what needs to be done at a contaminated site or with contaminated drinking water to get their exposure (and thus risk level) below that number. This could mean filtering water or removing topsoil at site (to avoid incidental ingestion of contaminated soil or to avoid breathing in soil particles). What kind of treatment and how much treatment is needed to get below that concentration? That is one of your design requirements. Similarly the design and operation of water treatment plants is based on cleaning water such that the water has less than some amount of a contaminant before it is sent via pipes to the customers. Design requirements from water treatment plants is generally based less on risk calculations and more on state and federal requirements for contaminant levels in drinking water. These federal requirements are called Maximum Contaminant Levels. Water treatment plants must meet these requirements, and they are designed to prevent the people who drink that water from getting sick from microorganisms or chemicals in the water.

This leads me to designing a HVAC system with HEPA filters or the use of portable HEPA filters in buildings to protect against COVID-19. In order to design a system, you have to know the design requirements. It is absolutely fine to say you want to reduce virus particles in the air and reduce transmission, but that is not a design requirement. Reduce is a vague, qualitative word. Engineering requires quantitative requirements. If you only want to reduce particles in the air, then you will only reduce the risk by an unknown amount with no clarity on if that reduction is an acceptable amount to the occupants of the building. Reducing risk could mean that instead of 30% of the occupants of a building getting sick, only 20% do. I personally don’t find that to be an acceptable reduction. A design requirement is based on what concentration of virus particles can be in the air and no person gets sick from COVID-19. Perhaps your requirement would not be that stringent, perhaps you would be ok with one in a thousand people getting sick from COVID-19 based on the design. The design requirement can be based on people wearing a mask or not wearing a mask. Maybe with everyone wearing a mask indoors, they can be exposed to 10 virus particles per hour, but without a mask, they can only be exposed to 2 virus particles per hour. This is where infectious disease experts are needed to provide information as to the pathogenicity and virulence of the pathogen, which in this case is COVID-19. An engineer designing a HVAC or some other filtering system for a building is not the person to decide what those design requirements are. They need the infectious disease experts to state what concentration of a pathogen a person can be exposed to without getting infected. The concentration may be zero. The problem at this point is I don’t think we know how much COVID-19 a person can be exposed to without getting sick. Thus, if we don’t know how much COVID-19 a person can be exposed to without getting sick, how can we possibly design a system to prevent a person from getting sick.

I can already hear arguments that we just need to do something. We need to accept some risk but do some things to reduce risk, so we can get things back to normal. I don’t think most business owners are going to be willing to spend a non-negligible amount of money on some design that will simply reduce risk to an unknown and unproven amount. For a place of employment or a school, is it reasonable to ask people, especially children, to return to a building with an unknown risk if a system has been put in place that reduces the risk an unknown amount? How much money should employers and educational boards spend to reduce risk an unknown amount? If you are willing to accept some risk, then why spend money on something that may reduce risk by some unknown amount? Everyone is already spending money on masks, gloves, hand sanitizer, etc. which at least has been proven to reduce risk, but not eliminate it, by a reasonable degree from a cost benefit perspective. I spent $20 or something on two reusable cotton masks that I wash after use. That is a very reasonable cost benefit amount from my perspective even though I can’t calculate the risk reduction of the mask. How much money is reasonable to invest in either a whole system HEPA filter or portable HEPA filters when the risk reduction is unknown? An extremely quick internet search provides options for portable HEPA filters from $200 to $1200. Should schools buy one per classroom, even at the low price end, when there is no data to show they would reduce risk at all? The point is, reducing risk is good, but if you going to invest money to reduce the risk, it would be prudent to determine how much the risk is actually going to be reduced before you do it.

PPE Basics

Posted on March 21, 2020 by geek

People are scared by COVID-19. This is understandable. Some people have started wearing personal protective equipment (PPE), mainly masks and gloves, although some are going for bonus points PPE like protective overalls, because they think the PPE will help protect them from COVID-19. It may, but it may not. I thought I might present just a few basics points for people who don’t normally wear to consider about wearing PPE.

What do I know about PPE you may ask. I am engineer and scientist. I have worn PPE in the field when taking environmental and industrial hygiene samples including soil, groundwater, urine, blood, air samples, and more. To earn my Ph.D., I worked in a lab that handled both chemical and biological samples. That is, one day I might have been handling urine or blood and needed to protect myself from pathogens, and another day I might have been handling chemical samples (or more likely part of a biological sample that had been placed into a chemical for processing) and needed to protect myself from chemical hazards. I am also HAZWOPER certified, and as part of the training, you have to dress in Level A and Level B PPE.

The most basic thing you need to know about PPE is first that PPE is essentially anything you wear that protects you from a hazard. In some places, jeans and long sleeves are PPE because they cover your skin from minor hazards. Steel-toed, leather boots are PPE that I have worn on a frequent basis when in the field as they protect my feet from many physical hazards including in at least one location I was working, rattlesnakes. [Not a hazard I was expecting on that site inspection, but, well, Texas.]

The second most basic thing you need to know about PPE is that it is not magical. PPE has to be worn correctly, and the correct PPE must be worn. For example, not all gloves protect against all hazards. In most of my work, I have worn nitrile gloves. Nitrile tent to be preferred over latex. The minor reason is potential latex allergy. However the main reason is that nitrile protects against more chemicals than latex. For most of my work, it is chemicals for which I need to protect myself. Most gardening gloves will protect you against some physical hazards like prickly vines, but they will not in general protect you against chemicals like pesticides you might be applying.

On the subject of gloves, gloves do not kill bacteria or viruses. If you are worried about viruses getting on your hands because you are touching a grocery cart for example, and so you decide to wear nitrile gloves, if you dispose of the gloves after touching the grocery cart and don’t touch anything else, then gloves may have protected you. However, if after touching the grocery cart with the gloves, you then touch your phone or your face with the gloves, then the gloves have done you no good. You have just transferred any viruses from the grocery cart to your gloves to your phone or face, just as efficiently as if you had not worn gloves. A week ago, I went to Costco and went first to the bathroom. When I was washing my hands, I noticed a woman washing her hands while wearing latex gloves. I simply don’t want to know what else she touched with the gloves before doing this or after.

A final note about gloves, there is a definite technique to how to remove them. The goal is to remove them without touching the outside of them. There may possible be another way, but the best way I have found to do it, is place one gloved finger on the outside of the other hand’s glove, near the wrist and carefully pull that other hand’s glove off, sort of rolling it off. Then with the now glove free hand, place your ungloved thumb under the other glove near the wrist and pull that glove off. Easier to show than explain.

Masks and respirators are designed for different types of protection, and it is critical that they be worn properly and for the correct use. Surgical masks are really more to the protect the patient from the surgeon sneezing or coughing on them than to protect the surgeon from the patient. Surgical masks can protect the wearer from splashes or larger droplets or to a certain extent large particles, but that is about it. Surgical masks do not provide even a decent seal around the face, so they do not protect from airborne viruses, bacteria, chemicals, or even small particles. If you don’t believe me, believe the FDA.

The now popular N95 masks can protect against some particles, viruses, and some other things if worn correctly. First, it is important to consult the manufacture’s information as to what they are designed to do and not to do. Second, it is critical that the wearer has a good seal. What does that mean? It means the edges of the masks must fit snugly against the skin for the entire perimeter of the mask. Men, you have to be clean shaven. Even an evening stubble will prevent the seal. N95 masks have a piece of metal that goes over the nose. That metal needs to be adjusted to get a good seal over the nose. Both elastic bands for the mask must be used to increase the fitness of the seal. Finally, masks get saturated. They can only be worn for a certain period of time before whatever you are breathing in breakthrough the mask.

I can’t emphasize enough how critical seals are. When I was graduate school, for the field work I was doing, I needed to be able to use a half-face respirator. That required me to first get medical clearance to wear the respirator. Second, I had to be fit-tested for the specific respirator I was going to wear. Different manufacturers make different size masks, and they don’t generally agree with each other. Hence I was fit-tested to wear a specific manufacture’s specific sized mask, and that was the one I wore throughout my field work.

Finally with respirators and masks also, the manufacture will state what the respirator or mask is designed to protect you from. If you go to a hardware store and look at respirators, you will notice that some respirators are for lead, some for particulates, some VOCs, and some will do a combination. A mask to protect from VOCs and PM10 is common. If you are going to work with VOCs, and you get one that is only for PM10, you will not be protected at all. Cartridges for respirators have to be changed frequently. Every two weeks is a common changeout time.

Those are the basics. There is really a lot more to understand about PPE, but those of the initial basic critical points to understand if you are thinking about wearing PPE to protect you from a virus or other hazards.

WMATA L’Enfant Plaza Fire

Posted on January 13, 2015 by geek

Today there was a fire in a WMATA subway tunnel near L’Enfant. The National Transportation Safety Board (NTSB) is now investigating, and I have confidence that they will do a thorough investigation. I have some questions about actions taken right after the smoke was reported that no one, or at least no one in the media I have seen, has asked. The station filled with smoke, and they evacuated it. WMATA stopped running green and yellow trains through L’Enfant. However they kept running blue, orange, and silver trains through, but these trains did not stop at the station, as they normally would. For those not familiar with L’Enfant Plaza Metro Station, orange, blue, and silver lines share the same track on the lower level, and yellow and green share the same track on the upper level. My question is, were they sure it was safe to keep sending the orange, blue, and silver trains through? I am not asking from the standpoint of the fire, because presumably, they traced the location of the smoke enough to know it was not in the lower tunnel. By safe, I mean because of the potential inhalation of smoke in the lower level tunnels. If the station filled with enough smoke that it needed to be evacuated, then how were they sure that smoke would not enter the trains running through it?

A couple of quick points:

Just because air smells bad doesn’t necessarily mean it is toxic or hazardous, but conversely, just because air smells fine doesn’t mean it is safe.
Particulate matter in air and/or smoke is in general not something you really want to breath, but there are different levels of toxicity associated with it. That is, some particulate matter is not more than just an irritant. However, the effect particulate matter has on a person is also affected by that person’s health. People with respiratory issues are more susceptible to any effects.
Exposure to hazardous or toxic materials can cause effects on different time scales. People who were trapped on the WMATA train in the tunnel, would have acute (short-term) effects from breathing the smoke, such as coughing and having trouble breathing. However, they were probably also exposed to chemicals whose effect is not immediate, such as carcinogens.

The questions I have, that I have not heard anyone ask include:

What is the air exchange rate between the subway trains and the surrounding air? Can the ventilation be turned off manually, so that there was no air exchange between the train and the surrounding air while the trains were near L’Enfant?
Were there any measurements taken of the air in L’Enfant, particularly on the lower level where the orange, blue, and silver trains were still running through? If so, what were the measurements of? Just measuring particulate matter will not indicate almost nothing about organic compounds or other chemicals in the air.
How far did the smoke spread?
Assuming air measurements were taken, did anyone calculate the amount of contaminants that people in the trains would be exposed to while running through the station based on time and air exchange rate?

My educated guess is that no air measurements were taken. There are probably some sensors in place to measure smoke, but depending on how that measurement is taken, it will tell you information about the particulate matter and that is it. I seriously doubt there was initially any sensors that measured organic compounds or any other type of compounds in the air. I have my doubts that any portable system was put in place during the response. The priority would have been evacuating people (as it should have been). It is possible that WMATA had some qualitative data that there was not much smoke on the lower level. That is, someone may have looked at a video screen and decided the air didn’t look bad. However, unless they had actual quantitative data of what was in the air, then visual assessment of air is a really bad way to make assessments on the quality of the air.

The early statements by WMATA and all other sources, like the fire departments involved, was that they did not know the source of the fire, location or cause. Thus they could not have possibly known what was burning and what would be in the air. For example, if wood is burning, you can expect certain chemicals in the air. If rubber is burning, you can expect different chemicals in the air. WMATA probably decided that the air on the lower level didn’t look that bad, and the trains would go through the station quickly enough that very little exposure would occur. They very well may be right, but with no data and no statements about any calculations, they have no way to prove that. Also, did they inform their passengers of this? If I was on a train, and I knew that the train was going to go through, but not stop, at a station that was filling with smoke, I would get off the train. I don’t feel the need to expose myself unnecessarily to hazardous substances, even if in small amounts. I do not like standing near people who are smoking. The second hand smoke may only minimally increase my risk of disease, but I still don’t see the need for that tiny increase. Thus, was WMATA considering passengers’ exposures at all? Furthermore, did they communicate the possibility of exposure to their passengers on the orange/blue/silver lines to allow their passengers to make their own educated decision about staying on the train? My guess is the answer to both those questions is no, and that is another thing to which WMATA should be made to respond.

Run the Chesapeake Bay Bridge 10K

Posted on November 11, 2014 by geek

View of the Chesapeake Bay Bridge near the start of the race

On November 9, 2014, I ran the inaugural Across the Bay 10k Chesapeake Bay Bridge Run. The point to point course includes 4.35 miles across the bridge, which reaches 186 feet at its peak. The run across the bridge provided amazing views of Chesapeake Bay. As an engineer, I really loved being able to examine the bridge up close at a slower pace than when driving across it. I wore a GoPro Hero 3+ on my head during the race to make a video of the run. I have edited the video to only include the start, bridge portion of the run, and the finish, and I have also sped up the video. My official run time was 1:16:24, and nobody wants to watch a video that long of me running across the bridge. I removed the sound due to a weird noise that was created when I sped up the video. Also, I took a few photos with my iPhone and made a few photos from freeze frames from the GoPro video.

View of the bay from the bridge

View of both bridges

In the truss section of the Chesapeake Bay Bridge

They also gave us a pretty cool medal for completing the race.

Completion medal

For My Safety

Posted on February 18, 2014 by geek

Like probably many health insurers, my health insurance company encourages me to use a mail order pharmacy for my maintenance drugs. As encouragement to use it, with the mail order pharmacy, I can order a 90 day supply, but only pay a co-pay for 60 days. Most of my maintenance drugs are actually generic, and I get generic drugs for free, so the only real advantage to me using the mail order pharmacy is laziness. I admit it is kind of nice just to log onto the website, hit refill, and have the drugs sent to me. At the beginning of the year, my insurance company switched to a different mail order pharmacy, so for most of my prescriptions, I have had to submit requests to my doctors for new prescriptions. Annoying, but no big deal, until I started getting them filled. I have rosacea, and I take one oral medication for it as well as using two face creams and one face wash, all prescriptions for it. I had my dermatologist call in a new prescription for the oral medication, and when it came from the mail order pharmacy, they only sent 34 pills with a note saying they had reduced the amount for my safety. The pill (Oracea) is designed and approved by the FDA as a maintenance drug for rosacea. It is supposed to be taken everyday. It is a low dose antibiotic taken for its anti-inflammatory properties. I don’t know of any way to get high off of it, not that I have tried. After a long conversation with the pharmacy trying to ascertain why they deemed this not safe enough to send me more than 34 pills, even though I have been taking this pill for well over a year, or for that matter why they sent me the strange amount of 34 pills, as opposed to 30, the pharmacy stated it was my insurer who decided this was not a maintenance drug. A call to my insurer resulted in me being told I would essentially need to petition them to recognize what the FDA calls a maintenance drug, as a maintenance drug. They also said I could go to my retail pharmacy and get the same deal they offer through the mail order pharmacy of a 90 day supply for the cost of 60. Why they offer this deal through the retail and thus what is the point of trying to get me to use the mail order pharmacy is not something I could understand, and if I continued to try to talk to them, I was going to need a drink. I gave up.

Now, however, my health insurer’s and the mail order pharmacy’s concern for my safety has gone to comical levels. As I said above, I also use a prescription face wash for my rosacea. It is a cleanser with sodium sulfacetamide and sulfur in it. It is an old formula and has been used by rosacea sufferers and people with other skin issues for decades. I have used it for at least two years, and I think it helps a bit. Because it is such an old formula, there are of course generics, to which my insurer automatically switches my prescription. I don’t care, and I get the face wash for free because it is generic. I had my dermatologist send in a new prescription to the mail order pharmacy, and it arrived today. Just in case you can’t guess, enclosed with the 12 oz bottle of face wash, was a note that reads as follows.

“Enclosed is a reduced quantity of your prescription drug. Your prescription drug coverage has quantity limits for certain drugs. This is a type of drug coverage review that limits how many doses you can receive. The goal is to make sure you get a safe amount of your drug.”

That’s right, they sent me a reduced quantity of my sulfur face wash for my safety. Thank goodness because otherwise I might wash my face too many times. It’s true. Washing your face with sulfur can get quite addictive. I love the smell of sulfur. (It actually does have a slight smell of sulfur but nothing repulsive.) I get in the shower and just keep washing my face knowing that the wash is free. Of course, it bears pointing out that they sent me a 12 oz bottle. The earliest I can refill it according to the label is in three weeks. This 12 oz bottle will probably last me three months or more. I don’t really count. I just reorder when I need it. I really don’t know what my pharmacy and insurer thinks I do with this stuff. Maybe they think I have a really dirty face. I have no idea. I can’t fantom how someone misuses sulfur face wash. I don’t think I want to know. Maybe they are afraid I am going to drink the stuff. All I know is that if my health insurer and mail order pharmacy think they have to protect me from too large an order of sulfur face wash then there probably is no hope for humanity. As an engineer, I have stated on many occasions, I have to design for the stupid. Not even I thought people were this stupid. I guess I overestimate people.

Universal Blood Donor

Posted on December 12, 2013 by geek

I previously wrote how I decided to donate blood for the first time and live tweeted the hilarity of my nervousness during the event. Several weeks after that, I got my blood donor card. I was curious to see it because I wanted to know what my blood type is. When I got the card, I found out that I am O-negative (O-). I am a universal blood donor. I assume I have now been put on that blood donor hit list when the blood bank gets low. My blood donor card came complete with a photo of an infant’s foot to take home the fact that O- blood is often used to help newborns as well as trauma victims before their blood can be typed.

Why am I a universal blood donor? There are eight major blood types. The type refers to antigens present on the red blood cells. I say eight major blood types because there are actually more blood types than that based on various antigens found on the red blood cells, but when you donate blood, they type you based on ABO antigens and the Rh factor. With ABO antigens, there is O, A, B, and AB with O meaning the absence of A or B. You can only accept blood from someone who has antigens that you have on your own red blood cells or to say it another way, someone who does not have antigens that you don’t have. With Rh factor, you have that antigen or you don’t, so if you have it, you are Rh+ or Rh-. If you are +, then you can accept from people who have it or those who don’t. If you are -, then you can only accept from that who don’t have it. You can’t receive blood from someone with an antigen on their red blood cells that you don’t have or your immune system will quickly react very badly to that foreign antigen being in your body. If you still find this confusing, it works out like this.

Blood Type	US Population*	Can donate to:	Can receive from:
O-	9%	Everyone (O-, O+, A-, A+, B-, B+, AB-, AB+)	O-
O+	39%	O+, A+, B+, AB+	O-, O+
A-	6%	A-, A+, AB-, AB+	O-, A-
A+	31%	A+, AB+	O-, O+, A-, A+
B-	2%	B-, B+, AB-, AB+	O-, B-
B+	9%	B+, AB+	O-, O+, B-, B+
AB-	1%	AB-, AB+	O-, A-, B-
AB+	3%	AB+	Everyone (O-, O+, A-, A+, B-, B+, AB-, AB+)

*The population data is based on information from AABB.

Thus, as someone who is O-, I am a universal blood donor, but I only can receive blood from other O- people. AB+ people are universal blood recipients and can receive blood from anyone. All of this shows the importance of blood typing people before they know they will need blood. It also shows why on tv and the movies, whenever someone is rushed into an emergency room and needs blood, the medical staff scream for O- blood (plus it makes for drama). Until they have time to type the patient’s blood, they can safely give the patient O-. Thus the information on my O- blood donor card that informs me it is particularly important for me to donate blood for those emergency room patients and of course the babies whose feet are on my card. It’s a nice little guilt trip to get me to keep donating.

The guilt trip worked. I gave blood again yesterday. It went a little better than last time because I wasn’t quite as nervous, but I admit I was still nervous. Unfortunately it didn’t go quite as well as it could. Last time, I used my left arm, but because I use the computer mouse with my left hand but write with my right hand, I decided to have them use my right arm this time. Evidently I have better veins in my left arm. The phlebotomist poked my right arm and couldn’t get the needle in well or something. He asked if he could take it out, which I readily agreed to because it was causing me pain. I switched chairs. He poked my left arm and found a good vein. I guess I need to find out how to build better veins in my arms. I survived. I felt fine afterwards, and I saved another life. That’s what really important.

38th Marine Corp Marathon

Posted on October 28, 2013 by geek

Yesterday, I watched the Marine Corp Marathon from a couple of different spots and cheered on the runners. Absolutely everyone of them has my respect. They inspired me to increase my Sunday long run from eight to nine miles. There is no way I can run a marathon, or at least not yet, but they inspired me to up my game. Below are a few of my photos that I took. Some runners are dressed in costume. Some military members are dressed in military gear including backpack. Some carried flags. One guy jump roped. One guy ran while juggling three footballs and dressed as Robert Griffith III because evidently running is just not a challenge (check out his photo below, as the best part is the look on the face of female runner next to him). At the end of this post is all the photos that I took on the extremely off chance that someone who reads this blog post knows someone in or was in the marathon and I by chance got their photo. If so, leave me a comment, and I will be happy to send you a copy.