Microconstituents in the Environment

Studies have shown that our nation's waters contain a broad range of chemicals and compounds that can cause ecological harm. As analytical test procedures continue to measure compounds in smaller and smaller concentrations, additional compounds are being identified in our waters. These products include both human and veterinary drugs, antibiotics, fragrances and cosmetics, soaps, fire retardants, pesticides and plasticizers (compounds which are used in a wide array of plastic products ranging from plastic bottles and eye glasses to sport safety equipment).

This drawing shows the pathway between homes and septic or municipal sewage facilities.Most of the products and compounds that have been developed and used by people will break down into their basic constituents (parts) and end up in the air, water or soil at some point. The term microconstituent is now being used to describe natural or manmade compounds that are detected in the environment with a potential effect on organism development and human health.

Recently Pharmaceuticals and Personal Care Products (PPCPs) have been highlighted as contributors of microconstituents in the environment. PPCPs are ubiquitous in our lives; millions of pharmaceuticals become wastes each year as products pass their expiration date, become unwanted, or unneeded. Ongoing studies reveal that pharmaceuticals are escaping into the environment and that some classes can act as endocrine disruptors, which have been linked to abnormalities and impaired reproductive performance in some species. Pharmaceutical wastes present both wastewater and solid waste management issues.


Disposal of Home Pharmaceuticals

Disposal of home pharmaceuticals flyers

This drawing shows some of the contributions of sewage, biosolids and farms to PPCPs in the environment.Many microconstituents enter the water from agriculture runoff and from people through bathing, hand washing, excretion (elimination of body waste) and by intentionally disposing of medications and personal care products down the drain (sink or toilet). Some of these products will break down and degrade, but others persist and travel through the sewer system to the waste treatment plant.

Wastewater treatment plants are typically designed to handle domestic waste, and are often not able to effectively treat all of the compounds that are in the wastewater they receive (influent). The wastewater discharged from a treatment plant (effluent) may contain small amounts of the microconstituents, which then end up in the groundwater, rivers, lakes and ocean. All of these water bodies are sources we use for drinking water.

All of us can work to reduce the amount of pharmaceuticals, personal care products and other microconstituents that end up in the water. Wastewater treatment plants are improving their technology to remove microconstituents. We can eliminate a source of microconstituents by not disposing of unused or expired medications down the toilet or drains.

Sources of PPCPsAt this time, the optimal way for individuals to get rid of unused or expired medications is to take them to a pharmaceutical collection event in the community. Check your city or county website for announcement of these events. DEQ will post information on the collection events or link to those that we are aware of on this page. Pharmaceuticals that are collected at these events will be incinerated.

If a collection event is not available in your locality, then the following procedure should be used:Drug disposal

  • Step 1. Empty the pill bottle into a closable plastic bag or container. Try not to handle the medications since some are absorbed through the skin. Crush the pills or dissolve them with liquid to render them unrecognizable as medications.
  • Step 2. Mix in something undesirable (suggestions: used coffee grounds, used kitty litter) with the medications that will not attract pets or children to it. Seal the baggie or close the plastic container. An additional safeguard would be to put the baggie of medications into another container so that the contents cannot be seen.
  • Step 3. Put the baggie or plastic container in the trash can.
  • Step 4. Remove the label or mark out your identifying information on the pill bottle label. This step is extremely important. The personal information found on prescription pill bottles is all someone needs to commit a crime. The label has the name of the medication, along with the name and address of the patient. Some pharmacists provide an informational page that has your identifying information in with the prescription that should also be destroyed after use. Don’t let yourself be a target of someone who may want your medications.

What other terms have been used to describe microconstituents?

Some other terms that have been used for these substances are:

  • PPCPs - Pharmaceuticals and Personal Care Products. PPCPs include:
    • Pharmaceuticals for human use (over-the-counter and prescription)
    • Pharmaceuticals for veterinary use (pets and agriculture)
    • Pet products and supplements (flea control, shampoos, vitamins)
    • Illicit drugs
    • Residues from medical facilities (hospitals, doctors’ offices)
    • Consumable supplements (caffeine, nicotine)
    • Nutraceuticals (vitamins and plant extracts)
    • Fragrances and cosmetics
    • Lotions, shampoos, soaps, deodorants, toothpaste, etc.
    • Sunscreen products
  • PhAC - Pharmaceutically Active Compounds
  • CPC - Compounds of Potential Concern.
  • PC - Pollutants of Concern.
  • EC or EP - Emerging Contaminant or Emerging Pollutant. These are chemicals that have been in existence as long as they have been commercially available. They may be newly formulated, or a new "combination form" of existing chemicals. We have just become aware of them because of problems seen in the environment, better analytical abilities and lower detection limits.
  • EDC - Endocrine Disrupting Compounds. An endocrine disruptor is a synthetic chemical that when absorbed into the body either mimics or blocks hormones and disrupts the body's normal functions. Examples are PCBs, pesticides, plasticizers, detergents, resins, etc. EDCs and PPCPs are not synonymous, but are two large groups of chemicals that intersect.

The terms above are more general than PPCP and include constituents that do not fall into the PPCP terminology such as:

  • Fire retardants - polybrominated diphenyl ethers, or PBDEs, commonly referred to as penta, octa, and deca
  • Bisphenol A - plasticizer
  • Phthalates - a group of chemicals used to soften and increase the flexibility of plastic and vinyl

What problems are attributed to microconstituents?

There have been a variety of problems found in wildlife that may be correlated to unusual levels of microconstituents in their systems. Examples of the physiological changes seen are intersex fish and frogs (the testes of males have female eggs), male birds with female organs, lobsters with shell growth and reproductive problems, and feminized male alligators. Behavioral changes have also been noted, such as loss of interest in mating seen in polar bears, and birds that do not want to tend to their eggs.

There is a growing body of evidence which indicates a rise in the incidence of disorders of the human reproductive system. For example, low sperm counts in young males living in the U.S. and other countries (phthalates being looked at), declining testosterone levels in men in age specific groups over the past 20 years, increases in testicular cancer in males and endometriosis in women, increases in the number of male babies are born with genital abnormalities every year in the U.K., and early onset of puberty in girls sometimes as young as 5 years old. The exact causes of the increase in reproductive problems are presently unknown. However, in parallel with the increase there has been a rise in the manufacture and use of many chemicals.

Researchers have tested pharmaceuticals to determine effective curative concentrations and toxic levels for the intended subject. However, it is important to realize that medications respond differently in different recipients. For example, a medication that is a pain reliever for humans and dogs can be lethal to cats. Pharmaceuticals are now being discovered in most of the waterways of the world, and are being ingested or absorbed by a diverse population of life forms. The effects of these compounds on non-target organisms is still being studied.

Even though microconstituents may degrade in a short time period, constant input via treated sewage and run off makes them appear persistent for chronic toxicity to aquatic organisms. The potential exists for subtle effects (e.g., neurobehavioral change), even at ppb levels (μg/L). Some effects may not be apparent for weeks, months, or years after initial exposure (delayed onset toxicity). This can complicate the research into determining the cause of noted effects.

There are many challenges in dealing with unknown toxicants, in unknown amounts, in varied conditions either singly or in combination with other potential toxicants. There is also the potential for additive (cumulative) and interactive (synergistic) effects from the multiple exposures. This is a very complicated issue with no easy answers.

Where can you find microconstituents?

ALL municipal sewage, regardless of location, will contain microconstituents. This issue is not unique to any particular municipal area. Each geographic area will differ only with respect to the types, quantities, and relative abundances of individual microconstituents. Microconstituents can be found in all tested waterways which are often the source for drinking water and bottled water. Refer to the USGS link below for their study where 139 rivers in 30 states were tested and found that 80 percent of them (111 rivers) contained 31 different drugs. Microconstituents can also be incurred by air deposits to water, or to living organisms by inhalation, ingestion or absorption.

Why didn't we notice these microconstituents before?

The scope of “testing for everything” is variable, and always increasing. Test methods are always improving, and the levels of detection are decreasing to where we can find things that were previously overlooked.

Testing for microconstituents is expensive. We tend to narrow the options by looking for ‘familiar’ things that have the potential to cause the problem seen. When those things aren’t present, we expand the search.

What one finds usually depends on what one looks for. Only those compounds targeted for monitoring have the potential for being identified and quantified. Those compounds not targeted will elude detection.

How do microconstituents get into the water?

PPCPs (Pharmaceuticals and Personal Care Products) can end up in the waters by these two methods:

  • Purposeful disposal of expired or unwanted medications and personal care products to the toilet, drain or trash.
  • Inadvertent disposal by excretion to sewage from humans (“pass-through”), pets, and agricultural sources (e.g., CAFOs – Concentrated Animal Feeding Operations)

Other microconstituents can end up in household dust and inhaled or ingested, or spread by air currents throughout the environment.

What can be done?

One of the most effective control strategies for preventing microconstituents from entering the environment is prevention. Prevention can take on many forms. One thing anyone can do is to use alternative cleaning products in their home. Cleaning solutions can easily be made with products that are commonly found in the home such as lemon juice, baking soda and vinegar.

For example, to make a less hazardous window cleaner add 2 tablespoons of vinegar to 1 quart of warm water and spray the mixture on windows and wipe dry. For a substitute to an all purpose cleaner mix ¼ cup baking soda and 1 quart warm water and wipe surfaces with a sponge and then dry. For more examples of alternative cleaning products, click the links below:

Unused and Expired Pharmaceutical Collection Events

Send your information (dates, times, location, specifics about what can or can't be accepted, point of contact and contact information, etc.) to Deborah DeBiasi with a link, and it will be posted.


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Virginia Department of
Environmental Quality
P.O. Box 1105
Richmond, VA 23218
(804) 698-4000


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