In addition to drugs and pesticides, which may be found in homes, there are numerous other substances that may be toxic if ingestion or exposure occurs.

Carbon Monoxide
CO as an industrial pollutant has been covered previously.  Sources of CO in the home may include automobile exhaust in enclosed garages, stoves, and heaters (gas or kerosene).  As with industrial CO, the primary reason for the formation of CO is the incompleat combustion of fossil fuels.
Mechanism of Toxicity -- CO binds avidly with hæmoglobin displacing oxygen from its binding sites to form carboxyhæmoglobin.  The association of CO with the hæmoglobin molecule, as a factor of relative CO and oxygen partial pressures, may be predicted by the Haldane equation.  Based upon this mathematical model, air that is 0.1% CO is capable of causing a 50% saturation of hæmoglobin.  This level of activity will be enough to cause hypoxia, ischæmia, and acidosis arising from anærobic respiration.  The primary danger of CO poisoning comes from the fact that it is odourless and colourless, making it difficult to detect.

Acute Toxicity -- Headache, confusion, agitation, nausea, vomiting.  The skin will become very pink.  As acute toxicity progresses, the patient will hyperventilate and become unconscious.  Finally, death usually occurs as a result of respiratory failure.  Necropsy reveals extensive areas of ischæmic damage.

Treatment -- Remove from the source of toxicity.  Breathing fresh air, the half-life of CO in the blood is approximately 250 min.  If the patient is given oxygen, the half-life shortens to 50 min.  If toxicity is severe, the patient may be placed in a hyperbaric chamber (2.5 G or atmospheres of pressure) and given oxygen, which shortens the half-life to 22 min.

Antifreeze
The two toxic components of antifreeze are ethlylene glycol and methanol.  (Not all antifreezes will contain both compounds.)  Ethylene glycol is very sweet tasting, which increases the risk of ingestion by children or pets.  Ingestion of 1 cup may prove fatal.  Methanol may also be found as a solvent in paints, shellacs, and varnishes.  The metabolic pathway that yeilds the toxic compounds and their physiologic effects are summarised below.


The dose of methanol that could produce blindness is approximately 15 ml.  Ingestion of 70-100 ml of MeOH may be fatal, if untreated.  The acidosis and accompanying pulmonary effects may cause a characteristic respiratory depression that is described as "fish-mouth", since it resembles a fish's ability to "breath" out of water.

Treatment for toxicity by either agent is ethanol or 4 methylpyrazole (fomepizole, ANTIZOL).  Since both compounds are metabolised by alcohol dehydrogenase into toxic metabolites AND since alcohol dehydrogenase has a greater affinity (100 times greater for EtOH vs. MeOH)  for ethanol, its administration (either oral or parenteral) will result in the preferential metabolism of ethanol, allowing the EG or MeOH to be excreted unmetabolised.  The dose of EtOH is loading 0.6 Gm/Kg followed by infusion of 10 Gm/hr for an adult patient.  The target plasma concentration of EtOH is 1 G/L, to ensure protection from MeOH toxicity.  4 Methylpyrazole is an inhibitor of alcohol dehydrogenase that acheives the same end without the detrimental effects of ethanol.
 

An interesting case study of EG toxicity is the Austrian Wine Scandal, in which vintners added small amounts of EG to their wine as a sweetener.  Interestingly, the presence of ethanol in the wine may have provided the natural antidote to EG toxicity, preventing widespread poisoning.

Ethanol and Solvents -- Refer to previous sections.

Household Cleaners -- NOTE that not all household cleaning products list the active ingredients.  Often times ingestion may not be treated adequately, because the specific toxic compound cannot be identified.  In addition to solvents, most cleaning supplies contain bleaches or surfactants.

Bleaches -- 3-6% sodium hypochlorite (pool products contain up to 20% Na hypochlorite)
Ingestion -- in the presence of stomach acid, hypochlorous acid is formed which is irritating to gastric mucosa and may cause vomiting.  Late appearance of œsophageal stenosis may also occur.

Inhalation -- severe irritation, cough, pulmonary œdema

Systemic toxicity (rare) -- hypotension, delerium, coma

Treatment -- For topical exposure, the skin should be flooded liberally with water.  For ingestion, the victim should be given milk, ice cream, or beaten eggs to dilute the bleach and antacids to neutralise the acid.  Na thiosulphate may also be administered, but signs of overproduction of hydrogen sulphide gas should be noted, since this may occur.
 

Anionic Detergents -- These surfactants are present in dishwashing liquids and shampoos.
Topical -- Overexposure to these surfactants will de-grease the skin (remove normal skin oils), which may cause dryness, redness, soreness, or even fissuring of the skin.  Individuals who are sensitive may exhibit weeping areas from cracks and fissures in the skin.

Ingestion -- Diarrhœa, abdominal distention, vomiting

Treatment -- Topical, flush with water to wash off well; Ingestion -- hasten the elimination by administering a cathartic
 

Nonionic Detergents -- Typically non-toxic

Cationic Detergents -- Disinfectants such as benzalkonium chloride, benzathonium chloride

Topical -- Very little toxic action with the skin

Ingestion -- Vomiting, collapse, coma, corrosive damage to the œsophagus, convulsions

Treatment -- Primarily supportive, may also administer soap (ordinary soaps are acceptable) to limit absorption.

Radon
Radon is a radioactive element that is carcinogenic and may also increase the risk of  pulmonary disease.  It may gain entry into the home from outside air, building materials, soil and rock beneath the house, and water supplies.  ²²²R degrades radioactively to ²¹⁶Po, ²¹⁴Pb, ²¹⁴Bi, and ²¹⁴Po (polonium, lead, and bismuth); all of which may also be toxic.
Upon inhalation of radon particles, the emission of alpha radiation may cause small cell undifferentiated lung cancer.  It is estimated that 7,000-30,000 lung cancer deaths/ year are attributable to radon toxicity.  In the U.S.A., the average indoor level of radon is 1.3 picoCuries/L (pCi/L) of air.  Outdoor levels are about 0.4 pCi/L.  The action level of radon, as set by the EPA is 4 pCi/L.  There are an estimated 60,000 homes with radon > 20 pCi/L, 1 million homes with >8 pCi/L, and 6 million >4 pCi/L.  A simple home test kit for radon may be purchased for about $25.00.  For more information, consult the EPA's homepage on radon.