Drug pollution

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Drug pollution or pharmaceutical pollution is pollution of the environment with pharmaceutical drugs and their metabolites, which reach the aquatic environment (groundwater, rivers, lakes, and oceans) through wastewater. Drug pollution is therefore mainly a form of water pollution.

Contents

"Pharmaceutical pollution is now detected in waters throughout the world," said a scientist at the Cary Institute of Ecosystem Studies in Millbrook, New York. [1] "Causes include aging infrastructure, sewage overflows and agricultural runoff. Even when wastewater makes it to sewage treatment facilities, they aren't equipped to remove pharmaceuticals." [1]

Sources and effects

Most simply from the drugs having been cleared and excreted in the urine. The portion that comes from expired or unneeded drugs that are flushed unused down the toilet is smaller, but it is also important, especially in hospitals (where its magnitude is greater than in residential contexts). This includes drug molecules that are too small to be filtered out by existing water treatment plants. The process of upgrading existing plants to use advanced oxidation processes that are able to remove these molecules can be expensive. Drugs such as antidepressants have been found in the United States Great Lakes. Researchers from the University of Buffalo have found high traces of antidepressants in the brains of fish. Fish behavior on antidepressants have been noted to have similar impacts and reducing risk-averse behavior, and thereby reducing survival through predation. [2] [3]

Other sources include agricultural runoff (because of antibiotic use in livestock) and pharmaceutical manufacturing. Drug pollution is implicated in the sex effects of water pollution. It is a suspected a contributor (besides industrial pollution) in fish kills, amphibian dieoffs, and amphibian pathomorphology.

Pollution of water systems

In the early 1990s, pharmaceuticals were found to be present in the environment, which resulted in massive scientific research, new regulations, and public attention. [4] Also during the 1990s, it was discovered that for the synthesis of one kilogram of an active pharmaceutical compound the amount of waste produced was fifty to hundred times that one kilogram, [5] which was ending up in the environment. During the late 1990s, estrogens were discovered in wastewater. It was concluded that this was the cause of feminization of fish. This was another factor that caused greater attention to pharmaceuticals in the environment. [6] Reviews and information on pharmaceuticals present in the environment date back to at least the 1980s. [7] The majority of pharmaceuticals are intended to cause slight adverse effects for the target population. [4] Low concentrations of pharmaceuticals can have negative effects on the freshwater ecosystems. [8]

Pharmaceuticals in the environment

In the United States, Spain, Germany and the United Kingdom over 101 different pharmaceuticals were present in ground water, surface water, drinking water or tap water. Between 30 and 100 different pharmaceuticals were found present in the aforementioned waters in Thailand, Canada, Australia, India, China, South Korea, Japan, Sweden, Poland, Italy, the Netherlands, France and Brazil. [8]

In rivers

In 2022, the most comprehensive study of pharmaceutical pollution of the world's rivers finds that it threatens "environmental and/or human health in more than a quarter of the studied locations". It investigated 1,052 sampling sites along 258 rivers in 104 countries, representing the river pollution of 470 million people. It found that "the most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing " and lists the most frequently detected and concentrated pharmaceuticals. [9] [10]

Pharmaceuticals and their effects

  • The excretion of oral contraceptives into freshwater ecosystems has caused fish and amphibians to feminize. [8]
  • Antipsychotics were created about seventy years ago and it was not until 2007 that it was reported that antipsychotics were present in the environment. They are used to treat a plethora of illnesses including depression, schizophrenia, autism, attention deficit hyperactivity disorder and bipolar disease. Antipsychotics, once excreted by the patient by either feces or urine, travel to wastewater treatment plants, which does not remove the drugs and their metabolites. These drugs have been found in drinking water, all bodies of water, and hospital sewage. Once they reach the aquatic environment, they possibly undergo bioconcentration and bioaccumulation through the food web. [11]
  • Psychiatric drugs, such as fluoxetine, sertraline, citalopram, chlorpromazine and oxazepram, were found to change fish behavior and caused disruption in the hormones of fish. In invertebrates, these drugs were found to cause reproduction toxicity and hormone disruption and alter their behavior. [8]
  • Antineoplastic drugs are employed during chemotherapy all over the world. They pollute water courses and have 'mutagenic, cytostatic, and ecotoxicological effects on the micro-organisms that are in the aquatic environment.' The wastewater treatment process is not able to remove antineoplastic drugs due to the intractable nature of them. Bodies of water that are contaminated with antineoplastic drugs possess grave consequences on the aquatic environment and even human health. [12] Chemotherapy drugs such as cyclophosphamide 1, fluorouracil, doxorubicin, cisplatin and mitomycin C were discovered to cause genotoxicity in aquatic organisms. [8]
  • Antibiotics are widely produced and consumed to treat bacterial and fungal diseases. Since antibiotics are only partially metabolized, the non-metabolized antibiotics are released into the environment. Due to this, antibiotics are discovered in sludge, drinking water, wastewater, surface water, soil, groundwater and sediments. Residual antibiotics are not easily biodegraded so, they can survive in environments for long periods of time. There are calls for an urgent push to eradicate antibiotics from the environment because they could cause generation of antibiotics resistant bacteria and antibiotics resistance genes, which would pose an immense threat to the ecological system and human health. [13] The excessive use and excretion of antibiotics to waterways makes the problem of antimicrobial resistance worse and will gradually affect the human population, possibly causing more deaths. [8] Antibiotics were found to reduce growth in algae, aquatic plants and environmental bacteria. [8]

Groundwater pollution

This section is an excerpt from Groundwater contamination by pharmaceuticals.[ edit ]

Groundwater contamination by pharmaceuticals, which belong to the category of contaminants of emerging concern (CEC) or emerging organic pollutants (EOP), has been receiving increasing attention in the fields of environmental engineering, hydrology and hydrogeochemistry since the last decades of the twentieth century. [14]

Pharmaceuticals are suspected to provoke long-term effects in aquatic ecosystems even at low concentration ranges (trace concentrations) because of their bioactive and chemically stable nature, which leads to recalcitrant behaviours in the aqueous compartments, a feature that is typically associated with the difficulty in degrading these compounds to innocuous molecules, similarly with the behaviour exhibited by persistent organic pollutants. [14] [15] Furthermore, continuous release of medical products in the water cycle poses concerns about bioaccumulation and biomagnification phenomena. [16] As the vulnerability of groundwater systems is increasingly recognized even from the regulating authority (the European Medicines Agency, EMA), environmental risk assessment (ERA) procedures, which is required for pharmaceuticals appliance for marketing authorization and preventive actions urged to preserve these environments. [17] [18]

In the last decades of the twentieth century, scientific research efforts have been fostered towards deeper understanding of the interactions of groundwater transport and attenuation mechanisms with the chemical nature of polluting agents. [19] Amongst the multiple mechanisms governing solutes mobility in groundwater, biotransformation and biodegradation play a crucial role in determining the evolution of the system (as identified by developing concentration fields) in the presence of organic compounds, such as pharmaceuticals. [20] Other processes that might impact on pharmaceuticals fate in groundwater include classical advective-dispersive mass transfer, as well as geochemical reactions, such as adsorption onto soils and dissolution / precipitation. [20]

One major goal in the field of environmental protection and risk mitigation is the development of mathematical formulations yielding reliable predictions of the fate of pharmaceuticals in aquifer systems, eventually followed by an appropriate quantification of predictive uncertainty and estimation of the risks associated with this kind of contamination. [19]

Assorted pharmaceuticals Assorted pharmaceuticals by LadyofProcrastination.jpg
Assorted pharmaceuticals

Prevention

Drug pollution still remains to be a global problem, since current policy techniques are not adequate enough. Most policy approaches remain to be individualized, expensive, and reactive. [8] Biomarkers could be extremely helpful in the risk assessment of pharmaceuticals for decision making in regulations. Biomarkers could help explain if a non-target organism was exposed to a pharmaceutical and the toxicity levels of the pharmaceutical in the organism if it is present. [4]

The main action for preventing drug pollution is to incinerate unwanted pharmaceutical drugs. Burning them chemically degrades their active molecules, with few exceptions. The resulting ash can be further processed before landfilling, such as to remove and recycle any heavy metals that may be present.[ citation needed ]

There are now programs in many cities that provide collection points at places including drug stores, grocery stores, and police stations. People can bring their unwanted pharmaceuticals there for safe disposal, instead of flushing them (externalizing them to the waterways) or throwing them in the trash (externalizing them to a landfill, where they can become leachate).

Another aspect of drug pollution prevention is environmental law and regulation, although this faces the problems of enforcement costs, enforcement corruption and negligence (see below), and, where enforcement succeeds, increased costs of doing business. The lobbying of pros and cons is ongoing. [21] [22]

Manufacturing

One extreme example of drug pollution was found in India in 2009 in an area where pharmaceutical manufacturing activity is concentrated. [23] Not all pharmaceutical manufacturing contributes to the problem. In places where environmental law and regulation are adequately enforced, the wastewater from the factories is cleaned to a safe level. [23] But to the extent that the market rewards "looking the other way" in developing nations, whether through local corruption (bribed inspectors or regulators) or plausible deniability, such protections are circumvented. This problem belongs to everyone, because consumers in well-regulated places constitute the biggest customers of the factories that operate in the inadequately regulated or inspected places, meaning that externality is involved.

Related Research Articles

<span class="mw-page-title-main">Chemical waste</span> Waste made from harmful chemicals

Chemical waste is any excess, unused, or unwanted chemical. Chemical waste may be classified as hazardous waste, non-hazardous waste, universal waste, or household hazardous waste, each of which is regulated separately by national governments and the United Nations. Hazardous waste is material that displays one or more of the following four characteristics: ignitability, corrosivity, reactivity, and toxicity. This information, along with chemical disposal requirements, is typically available on a chemical's Safety Data Sheet (SDS). Radioactive and biohazardous wastes require additional or different methods of handling and disposal, and are often regulated differently than standard hazardous wastes.

<span class="mw-page-title-main">Industrial waste</span> Waste produced by industrial activity or manufacturing processes

Industrial waste is the waste produced by industrial activity which includes any material that is rendered useless during a manufacturing process such as that of factories, mills, and mining operations. Types of industrial waste include dirt and gravel, masonry and concrete, scrap metal, oil, solvents, chemicals, scrap lumber, even vegetable matter from restaurants. Industrial waste may be solid, semi-solid or liquid in form. It may be hazardous waste or non-hazardous waste. Industrial waste may pollute the nearby soil or adjacent water bodies, and can contaminate groundwater, lakes, streams, rivers or coastal waters. Industrial waste is often mixed into municipal waste, making accurate assessments difficult. An estimate for the US goes as high as 7.6 billion tons of industrial waste produced annually, as of 2017. Most countries have enacted legislation to deal with the problem of industrial waste, but strictness and compliance regimes vary. Enforcement is always an issue.

<span class="mw-page-title-main">Water pollution</span> Contamination of water bodies

Water pollution is the contamination of water bodies, with a negative impact on their uses. It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from one of four main sources. These are sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. Water pollution may affect either surface water or groundwater. This form of pollution can lead to many problems. One is the degradation of aquatic ecosystems. Another is spreading water-borne diseases when people use polluted water for drinking or irrigation. Water pollution also reduces the ecosystem services such as drinking water provided by the water resource.

<span class="mw-page-title-main">Persistent organic pollutant</span> Organic compounds that are resistant to environmental degradation

Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic and adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released.

<span class="mw-page-title-main">Concentrated animal feeding operation</span> Type of American intensive animal farming

In animal husbandry, a concentrated animal feeding operation (CAFO), as defined by the United States Department of Agriculture (USDA), is an intensive animal feeding operation (AFO) in which over 1,000 animal units are confined for over 45 days a year. An animal unit is the equivalent of 1,000 pounds of "live" animal weight. A thousand animal units equates to 700 dairy cows, 1,000 meat cows, 2,500 pigs weighing more than 55 pounds (25 kg), 10,000 pigs weighing under 55 pounds, 10,000 sheep, 55,000 turkeys, 125,000 chickens, or 82,000 egg laying hens or pullets.

<span class="mw-page-title-main">Triclocarban</span> Antimicrobial agent

Triclocarban is an antibacterial chemical once common in, but now phased out of, personal care products like soaps and lotions. It was originally developed for the medical field. Although the mode of action is unknown, TCC can be effective in fighting infections by targeting the growth of bacteria such as Staphylococcus aureus. Additional research seeks to understand its potential for causing antibacterial resistance and its effects on organismal and environmental health.

<span class="mw-page-title-main">Ecotoxicity</span>

Ecotoxicity, the subject of study in the field of ecotoxicology, refers to the biological, chemical or physical stressors that affect ecosystems. Such stressors can occur in the natural environment at densities, concentrations, or levels high enough to disrupt natural biochemical and physiological behavior and interactions. This ultimately affects all living organisms that comprise an ecosystem.

<span class="mw-page-title-main">Sewage</span> Wastewater that is produced by a community of people

Sewage is a type of wastewater that is produced by a community of people. It is typically transported through a sewer system. Sewage consists of wastewater discharged from residences and from commercial, institutional and public facilities that exist in the locality. Sub-types of sewage are greywater and blackwater. Sewage also contains soaps and detergents. Food waste may be present from dishwashing, and food quantities may be increased where garbage disposal units are used. In regions where toilet paper is used rather than bidets, that paper is also added to the sewage. Sewage contains macro-pollutants and micro-pollutants, and may also incorporate some municipal solid waste and pollutants from industrial wastewater.

<span class="mw-page-title-main">Environmental impact of pharmaceuticals and personal care products</span> Effects of drugs on the environment

The environmental effect of pharmaceuticals and personal care products (PPCPs) is being investigated since at least the 1990s. PPCPs include substances used by individuals for personal health or cosmetic reasons and the products used by agribusiness to boost growth or health of livestock. More than twenty million tons of PPCPs are produced every year. The European Union has declared pharmaceutical residues with the potential of contamination of water and soil to be "priority substances".[3]

<span class="mw-page-title-main">Environmental impact of paint</span>

The environmental impact of paint can vary depending on the type of paint used and mitigation measures. Traditional painting materials and processes can have harmful effects on the environment, including those from the use of lead and other additives. Measures can be taken to reduce its environmental effects, including accurately estimating paint quantities so waste is minimized, and use of environmentally preferred paints, coating, painting accessories, and techniques.

<span class="mw-page-title-main">Environmental persistent pharmaceutical pollutant</span> Environmental term

The term environmental persistent pharmaceutical pollutants (EPPP) was first suggested in the nomination in 2010 of pharmaceuticals and environment as an emerging issue in a Strategic Approach to International Chemicals Management (SAICM) by the International Society of Doctors for the Environment (ISDE). The occurring problems from EPPPs are in parallel explained under environmental impact of pharmaceuticals and personal care products (PPCP). The European Union summarizes pharmaceutical residues with the potential of contamination of water and soil together with other micropollutants under "priority substances".

Cytostasis is the inhibition of cell growth and multiplication. Cytostatic refers to a cellular component or medicine that inhibits cell division and induce cell death.

Sex is influenced by water pollutants that are encountered in everyday life. These sources of water can range from the simplicity of a water fountain to the entirety of the oceans. The pollutants within the water range from endocrine disruptor chemicals (EDCs) in birth control to Bisphenol A (BPA). Foreign substances such as chemical pollutants that cause an alteration of sex have been found in growing prevalence in the circulating waters of the world. These pollutants have affected not only humans, but also animals in contact with the pollutants.

<span class="mw-page-title-main">Groundwater pollution</span> Ground released seep into groundwater

Groundwater pollution occurs when pollutants are released to the ground and make their way into groundwater. This type of water pollution can also occur naturally due to the presence of a minor and unwanted constituent, contaminant, or impurity in the groundwater, in which case it is more likely referred to as contamination rather than pollution. Groundwater pollution can occur from on-site sanitation systems, landfill leachate, effluent from wastewater treatment plants, leaking sewers, petrol filling stations, hydraulic fracturing (fracking) or from over application of fertilizers in agriculture. Pollution can also occur from naturally occurring contaminants, such as arsenic or fluoride. Using polluted groundwater causes hazards to public health through poisoning or the spread of disease.

Contaminants of emerging concern (CECs) is a term used by water quality professionals to describe pollutants that have been detected in environmental monitoring samples, that may cause ecological or human health impacts, and typically are not regulated under current environmental laws. Sources of these pollutants include agriculture, urban runoff and ordinary household products and pharmaceuticals that are disposed to sewage treatment plants and subsequently discharged to surface waters.

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<span class="mw-page-title-main">Groundwater contamination by pharmaceuticals</span> Aquifer contamination by medical drugs

Groundwater contamination by pharmaceuticals, which belong to the category of contaminants of emerging concern (CEC) or emerging organic pollutants (EOP), has been receiving increasing attention in the fields of environmental engineering, hydrology and hydrogeochemistry since the last decades of the twentieth century.

<span class="mw-page-title-main">Despo C. Fatta-Kassinos</span> Chemical and environmental engineer, academic and author

Despo C. Fatta-Kassinos is a chemical and environmental engineer, academic and author. She is a professor in the Department of Civil and Environmental Engineering and the first director of Nireas-International Water Research Center (Nireas-IWRC) at the University of Cyprus (2010–2022). She has been named a Highly Cited Researcher by Web of Science, Clarivate Analytics.

Joakim Larsson is a Swedish researcher primarily known for his studies on pharmaceuticals and antibiotic resistance in the environment. Since 2012, Larsson is a professor of environmental pharmacology at the Department of Infectious Diseases within the Institute of Biomedicine at Sahlgrenska Academy, University of Gothenburg.

References

  1. 1 2 HealthDay News journalists, "Antihistamines Adding to Drug Pollution in Streams", U.S. News, archived from the original on 2013-12-02, retrieved 2013-11-27.
  2. ↑ "Antidepressants are finding their way into fish brains". The Economist. Archived from the original on 2018-03-17. Retrieved 2018-03-18.
  3. ↑ Martin, Jake M.; Saaristo, Minna; Bertram, Michael G.; Lewis, Phoebe J.; Coggan, Timothy L.; Clarke, Bradley O.; Wong, Bob B.M. (March 2017). "The psychoactive pollutant fluoxetine compromises antipredator behaviour in fish". Environmental Pollution. 222: 592–599. doi:10.1016/j.envpol.2016.10.010. ISSN   0269-7491. PMID   28063712.
  4. 1 2 3 Ankley, Gerald T.; Brooks, Bryan W.; Huggett, Duane B.; Sumpter, and John P. (December 2007). "Repeating History: Pharmaceuticals in the Environment". Environmental Science & Technology. 41 (24): 8211–8217. Bibcode:2007EnST...41.8211A. doi: 10.1021/es072658j . ISSN   0013-936X. PMID   18200843.
  5. ↑ Kümmerer, Klaus (2010-11-21). "Pharmaceuticals in the Environment". Annual Review of Environment and Resources. 35 (1): 57–75. doi: 10.1146/annurev-environ-052809-161223 . ISSN   1543-5938.
  6. ↑ Larsson, D. G. Joakim (2014-11-19). "Pollution from drug manufacturing: review and perspectives". Philosophical Transactions of the Royal Society B: Biological Sciences. 369 (1656): 20130571. doi: 10.1098/rstb.2013.0571 . ISSN   0962-8436. PMC   4213584 . PMID   25405961.
  7. ↑ Murray-Smith, Richard J; Coombe, Vyvyan T; Grönlund, Marie Haag; Waern, Fredrik; Baird, James A (2012-01-13). "Managing emissions of active pharmaceutical ingredients from manufacturing facilities: An environmental quality standard approach". Integrated Environmental Assessment and Management. 8 (2): 320–330. doi:10.1002/ieam.1268. ISSN   1551-3777. PMID   22057894. S2CID   11765507.
  8. 1 2 3 4 5 6 7 8 Pharmaceutical Residues in Freshwater Hazards and Policy Responses (Report). OECD Studies on Water. Paris: OECD Studies on Water, OECD Publishing. 13 November 2019. doi:10.1787/c936f42d-en. ISBN   9789264776333. Archived from the original on 27 January 2021. Retrieved 23 July 2021.
  9. ↑ "Pharmaceuticals in rivers threaten world health - study". BBC News. 15 February 2022. Retrieved 10 March 2022.
  10. ↑ Wilkinson, John L.; Boxall, Alistair B. A.; et al. (14 February 2022). "Pharmaceutical pollution of the world's rivers". Proceedings of the National Academy of Sciences. 119 (8). Bibcode:2022PNAS..11913947W. doi:10.1073/pnas.2113947119. ISSN   0027-8424. PMC   8872717 . PMID   35165193.
  11. ↑ Escudero, J.; Muñoz, J.L.; Morera-Herreras, T.; Hernandez, R.; Medrano, J.; Domingo-Echaburu, S.; Barceló, D.; Orive, G.; Lertxundi, U. (May 2021). "Antipsychotics as environmental pollutants: An underrated threat?". Science of the Total Environment. 769: 144634. Bibcode:2021ScTEn.769n4634E. doi:10.1016/j.scitotenv.2020.144634. hdl: 10261/229106 . ISSN   0048-9697. PMID   33485196. S2CID   231693580.
  12. ↑ Yadav, Ankush; Rene, Eldon R.; Mandal, Mrinal Kanti; Dubey, Kashyap Kumar (January 2021). "Threat and sustainable technological solution for antineoplastic drugs pollution: Review on a persisting global issue". Chemosphere. 263: 128285. Bibcode:2021Chmsp.263l8285Y. doi:10.1016/j.chemosphere.2020.128285. ISSN   0045-6535. PMID   33297229. S2CID   225035554.
  13. ↑ Wang, Jianlong; Zhuan, Run; Chu, Libing (January 2019). "The occurrence, distribution and degradation of antibiotics by ionizing radiation: An overview". Science of the Total Environment. 646: 1385–1397. Bibcode:2019ScTEn.646.1385W. doi:10.1016/j.scitotenv.2018.07.415. ISSN   0048-9697. PMID   30235624. S2CID   52309095.
  14. 1 2 Calvo-Flores, Francisco G. (2018). Emerging pollutants : origin, structure, and properties. Weinheim, Germany. ISBN   9783527338764.{{cite book}}: CS1 maint: location missing publisher (link)
  15. ↑ Kummerer, K. (2004-07-01). "Resistance in the environment". Journal of Antimicrobial Chemotherapy. 54 (2): 311–320. doi: 10.1093/jac/dkh325 . PMID   15215223.
  16. ↑ Linlin, Yao (2017-01-01). "Occurrence and risk assessment of antibiotics in surface water and groundwater from different depths of aquifers: A case study at Jianghan Plain, central China". Ecotoxicology and Environmental Safety. 135: 236–242. doi:10.1016/j.ecoenv.2016.10.006. PMID   27744193.
  17. ↑ Committee for Medicinal Products for Human Use (CHMP. "Guideline on the environmental risk assessment of medicinal products for human use" (PDF). European Medicines Agency. Retrieved 15 June 2021.
  18. ↑ Wess, Ralf Arno (2021-03-01). "Update of EMA's Guideline on the Environmental Risk Assessment (ERA) of Medicinal Products for Human Use". Therapeutic Innovation & Regulatory Science. 55 (2): 309–323. doi:10.1007/s43441-020-00216-1. ISSN   2168-4790. PMID   32996106. S2CID   222155600.
  19. 1 2 Frega, Giuseppe; Macchione, Francesco (2020). Tecniche per la difesa del suolo e dall'inquinamento-Technologies for Integrated River Basin management. 41° corso. Edibios. pp. 253–266. ISBN   9788897181750.
  20. 1 2 Appelo, C. A. J. (2005). Geochemistry, groundwater and pollution (2nd ed.). Leiden: Balkema. ISBN   9780415364218.
  21. ↑ Gilbert, Natasha (2012-11-21), "Drug-pollution law all washed up: EU initiative to clean up waterways faces tough opposition", Nature News, 491 (7425): 503–504, doi: 10.1038/491503a , PMID   23172189.
  22. ↑ Editorial board (2012-11-21), "Water wars: environmental protections must not wait until a population is about to disappear", Nature, 491 (7425): 496, doi: 10.1038/491496a , PMID   23189323.
  23. 1 2 Mason, Margie (2009-01-26), "World's Highest Drug Pollution Levels Found In Indian Stream", Huffington Post, archived from the original on 2015-10-12, retrieved 2013-11-27.
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