Results

Explore CLEAR’s emerging contaminant data with the interactive dashboard below. Use the filter tab to search and explore specific compounds and use tabs below to navigate to plot data and create maps.

Frequency of Detection (2016 - 2017)

Frequency of detection in CLEAR’s samples from 2016-2017.

Atrazine, Sulfamethoxazole, Carbamazepine and Caffeine are the most frequently detected compounds in area waters during 2016 and 2017.

 

Chemicals Found in CLEAR MKE Samples (2016 -2017)

The chart below compares measured median detected compounds that we have found in our samples to reference median detection concentrations from different research. As we learn about concentrations of emerging contaminants in our water ways the work begins in order, to put the data in context, to understand what these levels mean for our waterways. PNEC is the predicted no effect concentration and tends to be a conservative number.

Sources 1: USGS, 2: Zuccato et al. 2010, 3: Kolpin et al. 2002, 4: Halden and Paull 2004, 5: EPA EcoTox database, 6: Blaise et al. 2006, 7: Fernandez et al. 2010

Sources 1: USGS, 2: Zuccato et al. 2010, 3: Kolpin et al. 2002, 4: Halden and Paull 2004, 5: EPA EcoTox database, 6: Blaise et al. 2006, 7: Fernandez et al. 2010

 

Below are examples of chemicals we found in our waterways and their potential effects.

Acetaminophen

Acetaminophen is a common over-the-counter medication used to treat pain and fever. It was found in less than 1% of our samples at a median concentration of 3ng/L, whereas it was found in USGS samples at a much higher frequency of 39% at a median concentration of 11ng/L. Acetaminophen's PNEC to cause toxicity is 20ng/L, which is about six times higher than our median concentration.

Amphetamine

Amphetamine is the main member of a group of illegal recreational drugs which cause an stimulant effect. It was found in 3% of our samples at a median concentration of 5ng/L. In a study of rivers in several Italian cities (Zuccato et al., 2005), there was no amphetamine found in any samples. Amphetamine's PNEC to cause toxicity is 28,800ng/L, which is several thousand times higher than found in our samples.

Atrazine

Atrazine is a pesticide which inhibits photosynthesis in certain types of plants. It is used in agriculture and gardening. Every year, 80 to 90 million pounds are used in the US alone (Ribaudo and Bouzaher, 1994). Atrazine can be toxic to fish and can cause cancer when found in high amounts. It was found in 47% of our samples at a median concentration of 3ng/L, whereas it was found in 68% of US Geological Survey (USGS) samples at a median concentration of 35ng/L. Atrazine's PNEC to cause toxicity is 4ng/L, which is only slightly higher than our median concentration, and almost half of our samples showed a concentration above this level.

Benzoylecgonine

Benzoylecgonine is the main metabolite (breakdown product) of cocaine. There are few data on its detection frequency or concentration from the US, but a large study of several medium-sized Italian cities found it in every sample they tested, with a median concentration of 0.75ng/L (Zuccato et al., 2005). We found it in about a quarter of our samples at a median concentration of 2.11ng/L, so a little more than double that of the Italian study. Thankfully, however, the lowest reported concentration that exhibits a toxic effect is 500ng/L, at which it has been found to cause non-lethal oxidative stress to zebra mussels (Parolini and Binelli, 2013).

Caffeine

Caffeine is the most commonly detected PPCP in Milwaukee's waterways, as well as surface waters around the world (USGS). It is a naturally occurring chemical found in many natural products such as coffee and tea, and it is classified as a recreational drug due to its stimulant effect. While it is commonly found in our water, studies have shown it has minimal effect at the concentrations found in our samples. Caffeine's NOEC was determined using crustaceans and algae and was found to be 5,200ng/L (Komori et al., 2013), which is more than 100x the median detected concentration in our data. However, there is minimal data that environmentally relevant concentrations (40.5ng/L) can decrease microbial respiration rates (Bunch et al., 2010).

Carbamazepine

Carbamazepine is a commonly used medication used to treat seizures and some types of pain. While the medication is commonly found in surface waters (USGS), it has little effect on the ecosystem at detected concentrations. The PNEC for carbamazepine is 420ng/L (Ferrari et al., 2003), which is more than 400x our median detected concentration for carbamazepine of 0.833ng/L.

Ciprofloxacin

Ciprofloxacin is a commonly prescribed antibiotic used to treat a variety of bacterial infections. It was found in 9% of our samples at a median concentration of 69ng/L, which is about half as often and half the concentration found in USGS samples. While our detected concentration is too low to cause direct toxicity (PNEC of 30,000ng/L), it is high enough to cause antibiotic resistance (Bengtsson-Palme and Larsson, 2016).

Cocaine

Cocaine is an illegal recreational drug which has a stimulant effect in humans. It is found naturally in the leaves of the coca plant, though at very low concentration. Its main metabolite is benzoylecgonine, another chemical we found in our samples. Cocaine was found in 13% of our samples at a median concentration of 6.6ng/L. This is less often but at the same median concentration as a study of waterways in several Italian cities (Zuccato et al., 2005). Our median detected concentration was several orders of magnitude smaller than what has been seen to cause an effect in the environment; that is, at concentrations above 20,000,000ng/L it can decrease phagocytosis in protozoans.

Cotinine

Cotinine is the main metabolite of nicotine (from tobacco) and does not occur naturally. It was found in 10% of our samples at a median concentration of 12ng/L. This is lower frequency and concentration as compared to what was found in USGS samples. This is also much lower than its PNEC of 589,500ng/L, above which it can cause decreased chlorophyll concentration in duckweed plants, thus causing decreased photosynthesis and energy production.

Diltiazem

Diltiazem is a prescription medication used to treat hypertension and several other heart conditions. It was found in 7% of our samples at a median concentration of 3ng/L, whereas it was found in 26% of USGS samples at a median concentration of 7ng/L. The detected level is much lower than the PNEC of 8,200ng/L, above which it can reduce the mobility of crustaceans.

Diphenhydramine

Diphenhydramine is a commonly used over-the-counter antihistamine medication used to relieve itching and allergies. It was found in 8% of our samples at a median concentration of 0.131ng/L, which is much lower in frequency and concentration than found in USGS samples. This is also lower than its PNEC of 2.4ng/L.

Gemfibrozil

Gemfibrozil is a prescription medication used to treat high lipid levels. It was found in 3% of our samples at a median concentration of 4ng/L. It was found in about the same number of USGS samples (4%), but at a much higher median concentration (48ng/L). Its PNEC to cause toxicity is 32,000ng/L, which is much higher than that found in our samples.

Metformin

Metformin is a commonly prescribed medication used to treat diabetes. It was found in 12% of our samples at a median concentration of 24ng/L, whereas it was found in 66% of USGS samples at a median concentration of 41ng/L. Our median detected concentration was much lower than the PNEC for toxicity of 64,000ng/L. However, while the detected concentration is too low to cause toxicity, it has been shown to cause endocrine disruption in fish in Lake Michigan (Niemuth and Klaper, 2018).

Ofloxacin

Ofloxacin is an antibiotic used to treat a variety of bacterial infections. It was found in less than 1% of samples at a median concentration of 0.07ng/L, whereas it was found in 8% of USGS samples at a median concentration of 9ng/L. This is much lower than its PNEC for toxicity of 10,000ng/L, as well as its PNEC to encourage antibiotic resistance of 500ng/L.

Oxacillin

Oxacillin is an antibiotic used to treat a variety of bacterial infections. As it is in the same class of antibiotics as penicillin, it is also usually not found in surface water samples, so the scientific literature is sparse on data regarding it. It was found in less than 3% of our samples at a median concentration of 2ng/L. In a study of water going into and out of a wastewater treatment plant and a river in Colorado (Cha et al., 2006), oxacillin was found in only two samples of the water going into the wastewater treatment plant at a concentration less than 20ng/L, and it was not found at all in the water coming out of the treatment plant or in the river. No data could be found about its PNEC to cause toxicity, but oxacillin's PNEC to encourage antibiotic resistance is 1000ng/L, which is 500 times our median concentration.

Paraxanthine

Paraxanthine is a metabolite of caffeine, which means it is produced when caffeine is digested by humans and animals. It does not occur naturally. Paraxanthine was found in 13% of our samples at a median concentration of 49ng/L, which is similar to the frequency of detection and concentration found across the US (USGS). Paraxanthine has fairly little effect on the environment. A study found it had no measurable effect on algae or fish but was lethal to water fleas at very high concentrations of 100,000,000ng/L (Fernandez et al., 2010). The concentration of paraxanthine found in our samples was nowhere near this high.

Penicillin

Penicillin is probably the most famous antibiotic, seeing as it was the first true antibiotic discovered. It was found in less than 1% of our samples at a median concentration of 13ng/L, which is below its PNEC to cause toxicity of 50ng/L. Interestingly, penicillin is not often detected in surface water samples due to its degradation in the wastewater treatment process (Gulkowska et al., 2008). The concentration necessary to encourage antibiotic resistance is unknown.

Roxithromycin

Roxithromycin is an antibiotic which treats bacterial infections including malaria. As it is not available in the United States, it is interesting that it was found in our samples, though it could come from tourists from countries where it is prescribed bringing it over on their vacation. It was found in 5% of our samples at a median concentration of 1ng/L. In a large study of rivers and streams in the US, roxithromycin was found in only .03% with a median concentration much higher than ours at 50ng/L. In addition, a much higher concentration than found in our samples is needed to encourage antibiotic resistance (64ng/L, Bengtsson-Palme and Larsson, 2016).

Sarafloxacin

Sarafloxacin is an antibiotic which was used to treat bacterial infections in poultry. However, it was pulled from the market by its manufacturer in 2001. This would explain why it was found in in less than 1% of our samples and in none of the samples in USGS' studies. However, in the few samples in which it was detected, its median concentration was 54ng/L. There is limited data on the concentration of sarafloxacin needed to cause mortality or antibiotic resistance, however, our detected concentration is three times sarafloxacin's PNEC to reduce chlorophyll production by algae.

Sulfadimethoxine

Sulfadimethoxine is an antibiotic used only in animals to treat a variety of bacterial infections. It was found in 4% of samples at a median concentration of 1ng/L, whereas it was found in 34% of USGS samples at a median concentration of 86ng/L. This is much lower than its PNEC for toxicity of 5,290ng/L. The concentration necessary to encourage antibiotic resistance is unknown.

Sulfamethoxazole

Sulfamethoxazole is an antibiotic medication used to treat bacterial infections. It was detected in about half of our samples, which is a similar frequency compared to national datasets; however, it was present at a lower median concentration (USGS). The PNEC for sulfamethoxazole to cause toxicity is 4,200ng/L, which is more than 100 times more than our median concentration. In addition, our detected concentration is below the PNEC to encourage antibiotic resistance (16,000ng/L, Bengtsson-Palme and Larsson, 2016).

Thiabendazole

Thiabendazole is a medication used to treat fungal and parasitic infections in humans and animals. It was found at a smaller frequency and concentration than in the USGS study (USGS). There is little published literature to date on specific toxic levels, though it is of high concern due to its high solubility and ability to be absorbed by soil, thus enabling it to remain in the environment for long periods of time (Long et al., 2005).

Triclocarban

Triclocarban is an antibacterial compound which was commonly used in soaps and lotions but was banned by the FDA in 2016 (FDA, 2016). USGS did not collect data on triclocarban, but a large study conducted in Baltimore, MD, found a median concentration in surface water of 81ng/L (Halden et al., 2004), whereas the median detected concentration in our samples was 9.2ng/L. While it is similar to its chemical cousin triclosan in function, triclocarban is much less toxic to the environment. It has been shown to decrease sea urchin larval growth at concentrations as low as 640ng/L and can cause morphologic abnormalities in sea urchin larvae at 1,600ng/L (Torres et al., 2016).

Triclosan

Triclosan is similar to its chemical relative triclocarban and was a commonly used antibacterial chemical in soaps and lotions. However, in 2016 the FDA banned it along with triclocarban (FDA, 2016). While triclosan was present at a much lower frequency in our samples than in USGS samples, our detected concentration was significantly higher at 114ng/L (USGS). Unfortunately, multiple studies have shown triclosan can have significant toxic effects on the ecosystem (specifically, algae and frog tadpoles) at concentrations of 150ng/L and can change phytoplankton community composition at concentrations as low as 15ng/L (Veldhoen et al., 2006; Wilson et al., 2003). While triclosan is one of the few chemicals present in Milwaukee's waterways at a concentration high enough to have negative effects, due to the fact it was banned, there is hope it will dissipate and not be a problem in the future.

Trimethoprim

Trimethoprim is an antibiotic used to treat bacterial infections in humans. It was found in 40% of our samples at a median concentration of 2ng/L, and it was found at a similar frequency in USGS samples (37%), but at a much higher concentration (52ng/L. Its PNEC to cause toxicity is 3,140ng/L, or about one thousand times more than what was found in our samples . Our detected concentration is also lower than the PNEC to encourage antibiotic resistance, which is 500ng/L (Bengtsson-Palme and Larsson, 2016).