Louise Pape’s life changed drastically in 1993. On a warm spring day, she and her husband were slowly driving home with the windows rolled down to en­joy the cool breeze. At the roadside she spotted a man from a tree care company wearing a gas mask and spraying pesticides on the trees with a large hose. Louise suddenly felt a shower of chemicals on her face, in her eyes, nose, and mouth, as the sprayer overshot his target. She later learned that the pesticide was a mixture of malathion and car – baryl (Sevin).

That incident was the beginning of a night­mare illness for Louise, an environmental planner who, ironically, had just finished developing a safe pesticide plan for her employer, a transnational corporation. She was disabled for several months with flu-like symptoms, aching joints and muscles, severe headaches, dizziness, thyroid problems, insomnia, and shortness of breath. She was of­ten bedridden and sometimes lapsed into a near comatose state upon reexposure to even minute amounts of pesticides. Louise eventually devel­oped full-blown multiple chemical sensitivity disorder. For four years, she was virtually home – bou nd, stil I unable to tolerate the trace amounts of pesticide and other chemical exposures that occur

EPA, in the face of overwhelming evidence of negative human health effects, does decide to ban a pesticide, the process is slow and fraught with compromise. For example, on June 8, 2000 the EPA agreed to phase out home and garden uses of chlorpyrifos,5 a known neuro­toxin that is the active ingredient in Dursban and Lorsban. Between 1991 and 1996, more than 17,000 cases of unintentional chlorpyri­fos exposure were reported to poison control during routine activities out in the world. Despite her illness, Louise and her husband have become articulate spokespersons in educating the public about the hazards of pesticides and other chemi­cals. The ranch home they built in 1995 has be­come a model for nontoxic living.

Discussion

Many of the most harmful pesticides fall into three categories: organochlorines, organophosphates, and carbamates. In the above case, the onset of ill­ness was associated with a single large exposure to an organophosphate and carbamate mixture. The cause of the prolonged illness was obvious. In most cases, however, the cause is not so obvi­ous. Many people are exposed to repeated low – dose applications of pesticides, which can result in general malaise with flu-like symptoms, chronic fatigue, and subtle neurological deficits. When patients complain of such symptoms to their doc­tors, they are rarely questioned about exposures to pesticides or other chemicals. Most emergency room doctors are familiar with acute pesticide poi­soning, but few physicians have knowledge of the long-term, chronic effects of pesticide exposure.

centers. Although less toxic and nontoxic al­ternatives are available for all chlorpyrifos ap­plications, more than 11 million pounds of the ingredient were being applied annually. The phase out allowed:

• home and garden use sales to continue through December 31,2001

• existing stock to be sold in retail outlets until depleted

• continued use on food crops (except to-

Gas, oil, coal, wood, and other fuels burned in­doors consume valuable indoor oxygen unless air for combustion is supplied from the out­doors. In tight, energy efficient buildings, these fumes can cause serious health consequences.

Indoor combustion is found in fireplaces; woodstoves; gas-fired appliances such as ranges, clothes dryers, and water heaters; fur­naces; gas – and kerosene-fired space heaters; and oil and kerosene lamps. Some of the po­tentially harmful emissions include nitrogen dioxide, nitrous oxide, sulfur oxides, hydro­gen cyanide, carbon monoxide, carbon di­oxide, formaldehyde, particulate matter, and hydrocarbons from natural gas fumes such as butane, propane, pentane, methyl pentane, benzene, and xylene. The indoor levels of these pollutants are determined by the amount of fuel burned and the rate of exchange with out­door air.

What are some of the potential health

effects of combustion byproduct gases? In a study of 47,000 chemically sensitive patients, the most important sources of indoor air pol­lution responsible for generating illness were the gas stove, the improperly vented hot wa­ter heater, and the furnace.2 Hazardous fumes can leak at the pipe joints and remain unde­tected, especially if they occur under floor­ing. In addition, every pilot light adds fumes, and the burning process itself releases fumes into the air. The primary effects of exposure to gas fumes are on the cardiovascular and ner­vous systems, but they can affect any organ of the body. Some of the earliest symptoms from exposure to gas fumes include depression, fa­tigue, irritability, and inability to concentrate.

Carbon monoxide is commonly produced during incomplete combustion, especially from gas-fueled appliances. Carbon mon­oxide quickly diffuses throughout the entire house. Typically, these appliances must be re­moved from the homes of chemically sensitive patients to restore their health. Chronic expo­sure can result in multiple chemical sensitivi­ties because carbon monoxide has the ability to interfere with the detoxification pathways in the liver, allowing the accumulation of toxic substances. Other effects of chronic carbon monoxide exposure include heart arrhyth­mia, decreased cognitive abilities, confusion, and fatigue.

Carbon dioxide is produced from burning natural gas. Elevated levels result in decreased mental acuity, loss of vigor, and fatigue. Nitro­gen oxides are also released from gas appli­ances. A major source of contamination is the gas stove, particularly older models with pilot lights. These gases are known to impact the nervous and reproductive systems.

Coal, gas, and woodburning fireplaces that are not equipped with sealed doors emit par­ticulate matter as well as toxic fumes. They also consume indoor oxygen unless fresh outdoor air is supplied to them. Particles not expelled by blowing or sneezing can find their way into the lungs, where they can remain for years.

It is important to mention that when an automobile is parked or operated in an at­tached garage, gas, oil, and other volatile or­ganic compounds diffuse into the structure and will affect air quality in the home. Garages therefore must be properly isolated from the main structure.

Well-ventilated and well-sealed sources of combustion can be operated with very little degradation of the indoor air. However, even sources of minimal exposure must often be re­moved from the homes of chemically sensitive patients to restore their health.

Pesticides

Although some pesticides may technically be considered VOCs, these often odorless and in­visible substances have become such a health threat that they warrant a separate discussion. Pesticides, or biocides, are poisons designed to kill a variety of plants and animals such as in­sects (insecticides), weeds (herbicides), mold (mildewcides), and fungus (fungicides). They were first developed as offshoots of nerve gas used during World War II. Most pesticides are synthetic chemicals made from petroleum. They are composed of active ingredients — the chemical compounds designed to kill the target organism — and inert ingredients — chemicals that deliver the active ingredients to the target, preserve them, or make them easier to apply.

Many people believe that the pesticides they buy, or those used by lawn and pest con­trol companies, are “safe.” They assume that the government is protecting them; that pes­ticides are scientifically tested; that if used ac­cording to the instructions on the label they will do no harm; and that the products would not be on the market if they were unsafe. All of these assumptions are incorrect.

EPA registration does not signify pesticide safety.3 The EPA approves pesticides based on efficacy, not safety. Efficacy means the pesti­cide will kill the targeted pest. Out of the hun­dreds of active ingredients registered with the EPA, fewer than a dozen have been adequately tested for safety.4 In fact, it is a violation of fed­eral law to state or imply that the use of a pesti­cide is “safe when used as directed.” When the

Indoor air pollutants can be classified into five main categories: volatile organic compounds, toxic byproducts of combustion, pesticides, electromagnetic fields, and naturally occur­ring pollutants. Each category of pollutant is described in a following section.

Volatile Organic Compounds

Organic compounds are chemicals contain­ing carbon-hydrogen bonds at the molecular level. They are both naturally occurring and

manufactured. Most synthetic organic com­pounds are petrochemicals derived from oil, gas, and coal. Organic compounds can exist in the form of a gas, a liquid, or solid particles. Substances that readily release vapors at room temperature are called volatile organic com­pounds (VOCs). This outgassing is a form of evaporation of volatile compounds contained in solid material and results in a slow release of chemicals into the air.

VOCs constitute a major source of toxic overload and can threaten individual health. Any organ of the body can be affected. Some of the more common symptoms include rashes, headaches, eye irritation, chronic cough, chronic sinus infections, joint and muscle pain, memory loss, inability to concentrate, irritability, fatigue, anxiety, depression, and an increasing number of allergies.

Organic compounds can be classified into three categories based on derivation from pe­troleum products. The primary organic com­pounds include components directly derived from gas, oil, and coal and include propane, butane, benzene, xylene, paraffins, toluene, and styrene. These products are then used to derive the intermediate substances such as formaldehyde, phenols, acetone, isopropanol, and acetaldehyde. The end products produced include solvents, waxes, lacquers, synthetic detergents, synthetic fibers, and paints. Com­mon sources of volatile organic compounds occurring in the indoor environment include:

• plywood

• particleboard

• wood paneling

• carpets and carpet pads

• insulation

• paints

• finishes

• solvents

• adhesives

• synthetic fabrics

• cleaning products

• body care products

• mothballs

• insecticides

• aerosol products

• art and hobby materials

• dry cleaned garments

• air fresheners

VOCs can also be generated from natural sub­stances. These include terpenes, which outgas from wood, and aromatics from natural oils. Some more chemically sensitive individu­als react to naturally occurring VOCs. These individuals are urged to test their reactions to each product before making a major pur­chase, even if the product is derived from a natural source.

You are undoubtedly familiar with the distinctive smell of a new house. The odor is composed primarily of outgassing chemicals from toxic volatile organic compounds. Some building products now report the parts per million of VOCs on their labels, but this infor­mation can be misleading. Yes, it is true that the fewer parts per million the better, but cer­tain chemicals such as dioxin are not safe in any detectable amount.1 One of the goals in constructing a healthy house is to reduce the use of toxic VOCs.