ISTC researchers examine the occurrence, fate and transport, and uptake into plants as well as mitigation techniques of PPCPs in the environment.
What are PPCPs?
The U.S. EPA defines pharmaceuticals and personal care products (PPCPs) as “any product used by individuals for personal health or cosmetic reasons or used by agribusiness to enhance growth or health of livestock.” This definition includes thousands of chemicals found in fragrances, cosmetics, over-the-counter drugs, and veterinary medicines. The U.S. EPA has identified PPCPs as emerging contaminants of concern because little is known about their environmental impacts or the risks they pose to human health when released into ecosystems.
Common PPCPs
- Caffeine (a bitter substance found in coffee, tea, soft drinks, chocolate, kola nuts, and certain medicines)
- Carbamazepine (an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder)
- Gemfribrozil (used to lower lipid levels)
- Ibuprofen (nonsteroidal anti-inflammatory drug (NSAID) that is commonly used to treat pain, swelling, and fever)
- Naproxen (used to treat pain or inflammation caused by arthritis, ankylosing spondylitis, tendinitis, and gout)
- Sulfamethoxazole (used to treat infections such as urinary tract infections, middle ear infections, bronchitis)
- Triclosan (antibacterial and antifungal agent found in consumer products)
- Estrogens (Estrone · 17α-Ethinylestradiol · 17β-Estradiol – the three main estrogens produced by the human body)
PPCPs can enter the ecosystem in a number of ways (Figure 1). For example, wastewater effluents from sewage treatment plants and large animal farms have been identified as major sources discharging these emerging contaminants into the surrounding water bodies. This is because many pharmaceuticals and supplements contain higher concentrations of chemical compounds than the human body or animals can process. Humans and animals process the chemicals to varying degrees. In some cases, we incorporate 95% of the active ingredient. In other cases, it’s closer to 5%. Either way, the body doesn’t use all of these chemicals, and some are excreted as waste or washed off into shower or sink drains. People may also dispose of unwanted PPCPs improperly by dumping them down the sewer or putting them in the trash. In addition to human-made PPCPs, humans and animals naturally excrete many hormones. These contaminants could pose a risk to both receiving ecosystems and drinking water resources.
In fact, PPCPs have been detected in many of the lakes, rivers, and streams in the United States, though usually at very low levels (ppb or ppt). PPCPs in groundwater and surface water affect water quality and can cause a series of negative effects on aquatic species. For example, steroid hormones are highly potent endocrine-disrupting chemicals (EDCs) which, even at levels as low as nanograms per liter (10-9 g/L or ppt), can adversely affect the reproductive biology of aquatic species.
Aquatic organisms may not be the only ones affected. PPCPs in water could be taken up by plant roots and may accumulate in the edible portions of the plant. As water supplies become increasingly scarce due to drought, climate change, and increased use, recycled wastewater for irrigation will become more common. However, using these contaminated waters for agricultural irrigation may introduce wastewater-associated antibiotics and pathogens to irrigated fields. This raises concerns about potential uptake and accumulation of PPCP contaminants in plants and their transfer up the food chain.
Figures: Ways PPCPs Enter the Environment
This drawing shows the pathway between homes and septic or municipal sewage facilities. – U.S. EPA
This drawing shows some of the contributions of sewage, biosolids and farms to PPCPs in the environment. – U.S. EPA