Category Archives: Household Science

Dressed for success … or distress?

People obsessed with dieting may be a little inconvenient on the subway (if you believe the rather dubious statistics in this news story), and diet pills may not work (or may give you tapeworm), but this made me wonder what other health problems could be associated with looking good.

Here’s a list of little-publicised problems…


A few decades ago, men wore suspenders to keep their trousers up. Now they use belts. The continuous constriction across the abdomen has been proposed as one reason for the increase in oesophageal cancers due to increased levels of acid reflux (a recent study has disputed this theory, however). Certainly wearing a back support belt (for lifting etc) has been shown to increase diastolic blood pressure. This suggests that the constriction caused by a regular belt may increase blood pressure and thus raise the risk of heart disease or stroke.


The wearing of a tight necktie can constrict blood flow across the neck. This has been shown to lead to increased pressure within the eyes and (by implication) within the head. Higher pressure in the eyes may increase the risk of glaucoma, and increased inter-cranial pressure could be a risk factor associated with strokes.

Let’s also not forget how much of a bacterial breeding ground a necktie can be. One particularly disgusting study looked at a contamination comparison between regular ties and bow ties worn by gynaecologists (no difference between the types of ties). Enough said on that topic.


Dressing fashionably in youth can lead to serious foot pain and deformity in later life.

Studies of shoe choice have shown that most men and women choose shoes far too narrow and often too short for their feet. Narrow shoes lead to corns, bunions and foot pain. Short shoes create toe deformities over time. High heels (above 2.5 cm) are also associated with bunions and painfully calloused skin. Poor shoe choice could also lead to higher risk of fall related injuries.


Let’s forget the corset of yesteryear. The tight support so often touted in underwear ads also has negative health impacts. Pressure from bras has been shown to slow digestion, reduce autonomic nervous system activity (responsible for organ functioning) and interfere with the temperature regulation of the body.

Tight underpants (and trousers) in men seem to be responsible for increased scrotal temperatures and reduced fertility. Even wearing boxer shorts rather than briefs may not solve the problem.

Nice Nails

Manicures, nail varnishes and acrylic nails all involve some level of exposure to organic toxins such as acetone and toluene. Linked to cancer, neurotoxity and respiratory problems, these chemicals may impact the wearer. Certainly people with a heavy exposure to these chemicals (such as nail technicians) show slight but significant decreases in cognitive reasoning, memory and learning ability.

Skirts and Pants

The type of skirt or pant you choose may increase risk of injury. Flowing clothing can lead to burns when people are incautious around open flames. Tight skirts and low-slung pants and trousers may impede movement and lead to more falls.


So does this mean that snazzy dressers are dumber, more deformed, spread disease and have lower IQs than slobs? I’m not sure I’m convinced – but I might point out these issues when next told to spruce up by my distant in-laws.


Biljan MM, Hart CA, Sunderland D, Manasse PR, Kingsland CR. (1993) Multicentre randomised double bind crossover trial on contamination of conventional ties and bow ties in routine obstetric and gynaecological practice. BMJ. 307(6919):1582-4.

La Vecchia C, Negri E, Lagiou P, Trichopoulos D. (2002) Oesophageal adenocarcinoma: a paradigm of mechanical carcinogenesis? Int J Cancer. 102(3):269-70.

Lagergren J, Jansson C. (2006) Use of tight belts and risk of esophageal adenocarcinoma. Int J Cancer.119(10):2464-6.

Leong SC, Emecheta IE, James MI. (2007) The flaming gypsy skirt injury. Injury. 38(1):122-4.

LoSasso GL, Rapport LJ, Axelrod BN (2001) Neuropsychological symptoms associated with low-level exposure to solvents and (meth)acrylates among nail technicians. Neuropsychiatry Neuropsychol Behav Neurol. 14(3):183-9.

LoSasso GL, Rapport LJ, Axelrod BN, Whitman RD. (2002) Neurocognitive sequelae of exposure to organic solvents and (meth)acrylates among nail-studio technicians. Neuropsychiatry Neuropsychol Behav Neurol.15(1):44-55.

Menz HB, Morris ME. (2005) Footwear characteristics and foot problems in older people. Gerontology 51(5):346-51.

Miyatsuji A, Matsumoto T, Mitarai S, Kotabe T, Takeshima T, Watanuki S. (2002) Effects of clothing pressure caused by different types of brassieres on autonomic nervous system activity evaluated by heart rate variability power spectral analysis J Physiol Anthropol Appl Human Sci. 21(1):67-74.

Munkelwitz R, Gilbert BR. (1998) Are boxer shorts really better? A critical analysis of the role of underwear type in male subfertility. J Urol. 160(4):1329-33.

Rafacz W, McGill SM (1996) Wearing an abdominal belt increases diastolic blood pressure. J Occup Environ Med. 38(9):925-7.

Teng C, Gurses-Ozden R, Liebmann JM, Tello C, Ritch R. (2003) Effect of a tight necktie on intraocular pressure. Br J Ophthalmol. 87(8):946-8.

Sanger WG, Friman PC. (1990) Fit of underwear and male spermatogenesis: a pilot investigation. Reprod Toxicol. (3):229-32.


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Just how dangerous is your morning shower?

In a previous post “That hot shower a little too relaxing?” I mentioned chloroform as one contaminant of shower water. It may seem rather amusing but remember that chloroform was banned as an anaesthetic as it was shown to cause heart attacks in people and kidney and liver tumours in animals.

Even if you don’t live in an area with heavy metal contamination, there are plenty of other chemical toxins in the water including carcinogens involving from chlorine and bromine.

But putting the chemicals aside for the moment, there are plenty more reasons why your morning shower may be one of the more risky things you do on a daily basis. One study by US researchers demonstrated a thriving bacterial culture growing on the average vinyl shower curtain. Taking advantage of that nutritious soap scum, charming guests such as those from the Sphingomonas and Methylobacterium families have been found. These are opportunistic pathogens who would love to infect any cuts or scrapes you may have.

What about mildew? Loving the damp walls and ceiling of your bathroom, those grey spots give off millions of spores. For asthmatics or people with an allergy to moulds, mildew build-up in bathrooms can be fatal. For the rest of us, the mycotoxins – chemicals produced by these moulds can cause lethargy, headaches and nausea.

Showers have other problems. Slippery when wet, many people injure themselves slipping or falling in the bath or shower. Cornell University estimates that more than one American is killed every day from such a fall (most over the age of 65).

Now add in the number of accidental drownings for infants and toddlers and serious scalds from hot water and you can see why the bathroom is considered the most dangerous room in the house.

So when you stumble bleary-eyed into the bathroom for your morning shower, don’t think cleansing, refreshing water, think Hitchcock’s Psycho with a larger arsenal.


Bennett JW, Klich M. (2003) Mycotoxins, Clin Microbiol Rev. 16(3):497-516.

Iksanova TI, Malysheva AG, Rastiannikov EG, Egorova IA, Krasovskii GN, Nikolaev MG. (2006) Hygienic evaluation of the combined effect of portable water chloroform, Gig Sanit. Mar-Apr;(2):8-12. In Russian.

Kelley ST, Theisen U, Angenent LT, St Amand A, Pace NR.(2004) Molecular analysis of shower curtain biofilm microbes. Appl Environ Microbiol.,70(7):4187-92.

Levesque B, , Tardif R, Ferron L, Gingras S,Schlouch E, Gingras G, Levallois P, Dewailly E.(2002) Cancer risk associated with household exposure to chloroform. J Toxicol Environ Health A. 65(7):489-502.

Murray JP. (1988) A study of the prevention of hot tapwater burns. Burns Incl Therm Inj. 14(3):185-93.

Nagano K, Kano H, Arito H, Yamamoto S, Matsushima T. (2006) Enhancement of renal carcinogenicity by combined inhalation and oral exposures to chloroform in male rats. J Toxicol Environ Health A. 69(20):1827-42.

Vittozzi L, Gemma S, Sbraccia M, Testai E. (2000) Comparative characterization of CHCl(3) metabolism and toxicokinetics in rodent strains differently susceptible to chloroform-induced carcinogenicity. Environ. Toxicol. Pharmacol. 8(2):103-110.

Weill Medical College of Cornell University (2006) Bathing For Older People With Disabilities


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Carcinogens – a BBQ sauce?

One of the most carcinogenic (cancer causing) thing you can eat is burnt meat. Yes, that crispy outside of your steak is as likely to give you cancer than anything else you put in your mouth.

It makes sense if you think about it. Meat is made of exactly the same proteins and chemicals as our bodies. Cook the meat and they start to break down creating reactive molecules very similar to healthy ones in our bodies. The nasties in this case are heterocyclic amines (HCAs) – shown to cause cancer in rats and listed as a carcinogen by the US government in 2005.

However burnt meat doesn’t contain much of this material so you’d have to love your BBQ a lot to worry. In fact, on a summer day, the sun could be more carcinogenic than the lunch.


Filed under Household Science, Kitchen Science

Diet foods – just how diet are they?

Artificially sweetened drinks and foods have become fashionable over the last decade or two (and not just for their volcanic reaction with Mentos).

Recommended by nutritionists to combat the growing effects of global obesity, they are the low-calorie alternatives to sugary soft drinks, sodas and sweets. Juices, confectionery and ice-creams are all offering low calorie alternatives sweetened with these compounds.

But how effective are they in reducing weight gain or promoting weight loss? On the surface, they seem very effective. Studies on rats [1] and people [3] have shown replacing sugary foods and drinks with the diet alternatives prevents, and can be used to treat, obesity. But not all studies are this rosy.

Diet foods/drinks may be able to fool the brain into thinking sweet foods contain less calories than they actually do. This could lead to over-indulgence of other foods as the brain loses the ability to correctly calculate the calorific intake of sweet foods (whether artificially or sugar sweetened).

A study on humans [2] showed that people who drank a sugared drink after exercise, reduced the calorie intake at a subsequent meal by the total amount of calories contained in the sugary drink. This showed that the brain is normally aware and can accurately calculate the calories regularly consumed. Those people given an artificially sweetened drink did not reduce consumption at a later meal – also implying that the brain was aware of the low-calorie nature of the fluid.

However, if people regularly consume low calorie sweets, this calorie calculation can be affected. A study using rats [4] demonstrated that those used to the “empty” calories of artificially sweetened drinks would consume more calories when given a sugary substitute than those who regularly consumed sugar – presumably because the brain had “re-calibrated” the calorie content of sweet foods.

Regularly consuming artificially-sweetened foods and drinks could therefore increase the consumption of calories on binge eating sessions by making the brain under-estimate the calorific load.

Thus consuming diet foods may not be (entirely) the calorie-saving option you’d hoped. It seems that the old advice about reducing the consumption of sweet foods and drinks and increasing exercise may be the only sure-fire way to diet.

But don’t fear, whatever their effect on your hips, they can be light on your pocket. Diet drinks can turn anyone into a cheap drunk. A recent study shows that drinks made with diet mixers are absorbed faster and thus the drinker will become drunker faster[5].


[1] Porikos KP, Koopmans HS (1988) The effect of non-nutritive sweeteners on body weight in rats. Appetite 11 Suppl 1: 12-15
[2] King NA, Appleton K, Rogers PJ, Blundell JE (1999) Effects of sweetness and energy in drinks on food intake following exercise. Physiol Behav 66: 375-379
[3] St-Onge MP, Heymsfield SB (2003) Usefulness of artificial sweeteners for body weight control. Nutr Rev 61: 219-221

[4] Davidson TL, Swithers SE (2004) A Pavlovian approach to the problem of obesity. Int J Obes Relat Metab Disord 28: 933-935
[5] Wu KL, Chaikomin R, Doran S, Jones KL, Horowitz M, Rayner CK (2006) Artificially sweetened versus regular mixers increase gastric emptying and alcohol absorption. Am J Med 119: 802-804


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That hot shower a little too relaxing?

A hot shower – one of life’s little pleasures. No matter how tense you are, a nice long, hot shower leaves you feeling more relaxed. But is it just the heat relaxing those tired muscles?

In chlorinated water, carbon molecules from your body or carbon naturally present from plant or animal matter in the water can combine with the added chlorine to form chloroform (CHCl3).

A powerful relaxant, chloroform was used as an anaesthetic during the first part of the 20th century – until the toxic side effects became more widely known.

The heat and splashing of the water in a shower allows the tiny water droplets in the air to be inhaled. You can also absorb chloroform from the water directly through the skin.

Thus part of the relaxation from a long, hot shower could well be chemical. You are partially anaesthetising yourself!

Jo W.K., Weisel, C.P. and Lioy, P.J. (1990) Routes of Chloroform Exposure and Body Burden from Showering with Chlorinated Tap Water, Risk Analysis, 10(4) 575.

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Gritty Pears

Beach picnics leave something to be desired. That gritty texture as the sand blows into the sandwiches; the added crunch in the ice-cream. Sand is comprised primarily of tough silica (silicon dioxide) crystals that resist the constant grinding of waves on a beach.

Have you ever noticed how pears in some ways resemble beach food? When you chew a pear, you can feel a rough, gritty texture. It’s very similar to sand contaminated food. In fact, the similarities do not stop at the texture. The gritty particles in pears are actually silica as well – produced in the sclereid cells of the tissue layer called the sclerenchyma.


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Better salad dressings?

Oil and water do not mix – usually – but under certain circumstances they can.

If you want to make a home-made vinegrette, you vigorously shake the olive oil and vinegar together. This will break the oil layer into tiny droplets mixed throughout the vinegar. A short while later, however, the little oil blobs will start to join together (coalesce) and reform the oil layer at the top.

In commercial salad dressings, an emulsifier (such as soy lecithin) stabilises these droplets in water (or vinegar) and allows the mixed product (emulsion) to remain for longer. Mayonaisse works by utilising the natural emulsifiers found in egg yolks in the same way.

But is it possible to create a stable emulsion without using an emulsifier?

One scientist believes it is. Pashley theorised that it wasn’t an intrinsic incompatability between the two liquids but naturally dissolved gases in the water which force the oil droplets to break away from the surrounding water molecules and regroup with other oil particles. (Gases naturally become dissolved when water comes into contact with air – for example fish use dissolved oxygen to breathe).

By repetitively freezing and thawing water and removing any expelled gas at each stage, Pashley created gas-free water .

When shaken with oil, a stable emulsion was formed which required no added emulsifiers. Even when the mixture was allowed to stand, thus permitting gases to dissolve back into the solution, the emulsion remained stable.

The mechanism however is still unknown so it’ll probably be a while before this pratice becomes commercially accepted.

Moral: If you want to make perfect salad dressings become a chemist.


Pashley, R.M. (2003) Effect of Degassing on the Formation and Stability of Surfactant-Free Emulsions and Fine Teflon Dispersions, Journal of Physical Chemistry B, 107(7): 1714-1720

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