Introduction

This section discusses additional sources and pathways of exposure to hazardous substances in the home and environment that the health care provider should consider when taking an exposure history. The clinician should also consider the following possible sources when eliciting information on exposures in the home and environment:

• Household products,
• Lead products and waste,
• Pesticides,
• Recreational hazards,
• Soil contamination, and
• Drinking Water supply.

For educational resources on these and related topics, please see "What Are Additional Environmental Health Resources?" section.

Household Products

The following household products are potential sources of exposure that should be considered when taking an exposure history:

• Aerosol sprays,
• Air fresheners,
• Automotive products,
• Candles (leaded wick),
• Cleansers,
• Disinfectants,
• Dry-cleaned clothing,
• Fuels,
• Hobby supplies,
• Moth repellents,
• Paint strippers and other solvents,
• Paints, and
• Wood preservatives.

EPA's Total Exposure Assessment Methodology (TEAM) studies found levels of about a dozen common organic pollutants to be 2 to 5 times higher inside homes than outside, regardless of whether the homes were located in rural or highly industrial areas. Commonly used compounds that can have serious adverse health effects are listed in the table below [US Environmental Protection Agency 2012a].

Table 3. Commonly Used Compounds that Can Have Serious Adverse Health Effects

Pesticides

Pesticides are potentially hazardous, especially to children. Pesticide exposure can occur through

• Dermal contact,
• Inhalation, or
• Ingestion.

According to a recent survey, 75% of U.S. households used at least one pesticide product indoors during the past year. Products used most often were insecticides and disinfectants. Another study suggests that 80% of most people's exposure to pesticides occurs indoors and that measurable levels of up to a dozen pesticides have been found in the air inside homes [US Environmental Protection Agency 2012a].

Exposure to high levels of cyclodiene pesticides, commonly associated with misapplication, has produced various symptoms, including

• Dizziness,
• Headaches,
• Muscle twitching,
• Nausea,
• Tingling sensations, and
• Weakness.

In addition, EPA is concerned that cyclodienes might cause long-term damage to the liver and the central nervous system, as well as an increased risk of cancer [US Consumer Product Safety Commission (CPSC) 2012; US Environmental Protection Agency 2012a].

Despite the ban on certain pesticides in the United States, exposure can still occur through improper

• Use,
• Storage, and
• Disposal.

Some banned pesticides are used in foreign countries and may return to this country on imported foods. There have been reports of unlicensed pesticide applicators in the United States spraying inside homes with pesticides intended for use in outdoor settings resulting in illness and even death [Wasley et al. 2002]. Proper use (including use of licensed pesticide applicators, following all product safety instructions, etc.) and storage of household pesticides in their original containers along with proper cleaning of food, especially raw fruits and vegetables, can help protect consumers.

Lead

Lead poisoning continues to be a significant health problem in the United States. Although lead was banned from paint for home use in 1978, millions of homes, particularly those built before 1950 still contain high amounts of lead in paint that is peeling and accessible for ingestion by children.

Lead has long been recognized as a harmful environmental pollutant. Humans are exposed to lead through many ways including through

• Air,
• Drinking water,
• Food,
• Contaminated soil,
• Deteriorating paint, and
• Dust.

Airborne lead enters the body when an individual breathes or swallows lead particles or dust once it has settled. Lead was used in

• Gasoline,
• Paint,
• Water pipes, and
• Many other products

Old lead-based paint is the most significant source of lead exposure in the United States today. Harmful exposures to lead can be created when lead-based paint is improperly removed from surfaces by

• Dry scraping,
• Open-flame burning, or
• Sanding.

Lead affects practically all systems within the body. At high exposure dose levels it can cause

• Convulsions,
• Coma, and
• Even death.

Lower exposure dose levels of lead can adversely affect the

• Brain,
• Central nervous system,
• Blood cells, and
• Kidneys.

The effects of lead exposure on fetuses and young children can be severe. They include

• Delays in physical and mental development,
• Increased behavioral problems,
• Lower IQ levels, and
• Shortened attention spans.

Fetuses, infants, and children are more vulnerable to lead exposure than adults since lead is more easily absorbed into growing bodies, and the tissues of small children are more sensitive to the damaging effects of lead. Children may have higher exposures since they are more likely to eat lead paint chips in addition to having lead dust on hands or toys/objects that they may place in their mouths. [Agency for Toxic Substances and Disease Registry 2005; US Environmental Protection Agency 2012a].

Additional information on this topic can be found in the "What are Additional Environmental Health Resources?" section.

Recreational Hazards

Recreational areas and products can pose a hazard to health.

The United States has made tremendous advances in the past 25 years to clean up the aquatic environment by controlling pollution from industries and sewage treatment plants. Today, nonpoint source (NPS) pollution remains the nation's largest source of water quality problems. It's the main reason that approximately 40% of our surveyed rivers, lakes, and estuaries are not clean enough to meet basic uses such as fishing or swimming [US Environmental Protection Agency 2012b].

Wooden playground structures that have not been treated with protective sealants may expose children to potentially hazardous wood preservatives. Chromated copper arsenate (CCA) is a chemical wood preservative containing chromium, copper, and arsenic. It is used in pressure treated wood to protect wood from rotting due to insects and microbial agents. CCA treated wood has a greenish tint and has been used in thousands of

• Decks,
• Picnic tables,
• Play sets, and
• Railings.

The EPA has worked with manufacturers since 2003 to eliminate CCA from children's play structures. Unfortunately, many older playgrounds still exist [US Envirronmental Protection Agency 2011].

Some play sands and clays have been reported to contain asbestos-like fibers. Other materials used in arts and crafts involve potentially hazardous:

• Heavy metals such as lead and cadmium,
• Silica,
• Solvents, and
• Talc.

Toxic materials may be encountered in

• Making stained glass and jewelry,
• Model building,
• Oil and airbrush painting,
• Soldering, and
• Woodworking.

Persons do not need to be directly involved in these activities to become exposed; merely being in the vicinity of a work area may lead to exposure.

Federal legislation (the Labeling of Hazardous Art Materials Act) requires that all chronically hazardous materials be labeled as inappropriate for children's use [US Consumer Product Safety Commission (CPSC) 1995].

Drinking Water Supply

Both contaminated public drinking water supplies and contaminated private wells may be sources of toxic exposure, especially for industrial solvents, heavy metals, pesticides, and fertilizers. For example, an EPA groundwater survey [US Environmental Protection Agency 1985] detected trichloroethylene in approximately 10% of the wells tested. It is estimated to be in 34% of the nation's drinking water supplies. Up to 25% of the water supplies have detectable levels of tetrachloroethylene. Some solvents can volatilize from showers and during laundering of clothes, thereby creating a risk of toxicity via inhalation. Nitrates, a common contaminant of rural shallow wells, pose a risk of methemoglobinemia, especially to infants [Agency for Toxic Substances and Disease Registry 1997, 2013].

Contamination of drinking water supplies may come from the source water and/or the distribution system after water treatment has already occurred. There are many potential sources of water contamination, including

• Local land use practices (fertilizers, pesticides, concentrated feeding operations),
• Manufacturing processes,
• Naturally occurring chemicals and minerals (for example, arsenic, radon, uranium), and
• Sewer overflows or wastewater releases.

The presence of contaminants in water may lead to adverse health effects if exposure occurs, including

• Gastrointestinal illness,
• Neurological disorders, and
• Reproductive problems.

Infants, young children, pregnant women, the elderly, and people whose immune systems are compromised (i.e., those with AIDS, undergoing chemotherapy, on transplant medications, etc.), may be especially susceptible to illness from some contaminants [US Centers for Disease Control and Prevention 2014].

Soil Contamination

Ingestion of contaminated soil poses a risk of toxicity, especially to children under the age of six, because of natural mouthing or pica behaviors. Lead is a common soil contaminant. Dioxin also adsorbs to soils. Certain pesticides such as chlordane can remain in the soil for years.

Sources of soil contamination include

• Agriculture,
• Chemical and microbial contaminants,
• Municipal wastewater (and associated biosolids), and
• Industry.

Chemical contaminants range from heavy metals like mercury to polychlorinated biphenyls (PCBs) to relatively new emerging contaminants. Sediments and soils may contain multiple chemical contaminants combined with microbial pathogens. Emerging contaminants of concern such as endocrine-disrupting chemicals (EDCs) that might be found in soil, may come from municipal wastewater, concentrated animal feeding operations (CAFOs) and other sources [US Envirronmental Protection Agency 2013].

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