Micropollutants: Tiny particles with toxic potential

Micropollutants: Tiny particles with toxic potential

03-02-2018 | Article
Micropollutants (MP) are the by-products of convenience in modern life. They are small chemical and biological compounds used in the millions of products produced by advanced economies. Conventional water treatment technologies are not designed to treat MP and their concentrations are increasing in ground waters and aquatic environments. Marine life are already suffering negative effects. Humans could follow. Fortunately, cost-effective technologies exist.
  • Dieter Küffer
    CFA, Senior Portfolio Manager, RobecoSAM Sustainable Water Strategy
  • Households alone flush or dump 70% of the pharmaceutical-related micropollutants present in municipal waterways.
  • More than 90% of China’s underground aquifers, supplying the country’s drinking water, are polluted.
  • Water treatment technologies have advanced over the past decade and a number of cost-effective and technologically-feasible solutions are available.

From obscurity to ubiquity

Though microscopic, micropollutants (MP) have out-sized potential for wreaking havoc on ecosystems and human health. They are tiny chemical and biological particles that make their way into the waterways of an increasingly sophisticated developed world. To the experts, they bear obscure names like Atenolol, Clarithromycin, Diclofenac, Diethyltoluamide, Isoproturon, Acesulfame and Methyl-benzotriazole.

We know them by their end-products — beta-blockers, antibiotics, anti-inflammatory drugs, fertilizers, insecticides, artificial sweeteners, laundry detergent. They are used to save lives, ease pain, enhance taste, protect crops, and promote well-being, alongside a host of other attributes of modern life. 

More than 143,000 chemical compounds were registered for commercial use in the EU alone.1,2 The US Toxicology Program reported 80,000 registered chemicals with an estimated 2,000 added each year.3 The list grows longer when you consider that new combinations are formed when these “registered compounds” are released in nature.

Major sources of micro-pollution

Households alone flush or dump 70% of the pharmaceutical-related MP present in municipal waterways. In the same way chemicals from personal care and cleaning products enter the system. Other sources include herbicides and insecticides from agricultural effluent as well as wastewater from industrial sources used to manufacture things like textiles and tires, paints and plastics, fuels and fragrances.

Households alone flush or dump 70% of the pharmaceutical-related MP present in municipal waterways.

Conventional waste water treatment systems were never designed to detect and filter these micro-sized contaminants, which means MP concentrations in oceans, ground water, estuaries, and even drinking water are increasing. With dwindling clean water supplies, water recycling and re-use will increase and micro-pollution along with it.

Damaging effects

Biological MP can be blamed for spreading antibiotic resistance in organisms, animals and humans—the UN estimates deaths from drug-resistant infections will rise to 10 million by 2050.5 Other micropollutants like endocrine disruptive chemicals (EDC) in wastewaters are responsible for estrogenicity (or “feminization”) of fish in marine environments and chemically-induced genetic mutations. They also impact the genetic integrity of DNA in organisms – a condition known as genotoxicity. EDCs are commonly found in pesticides, metals, food additives, and personal care products. 

Though evidence is still inconclusive, in humans, EDCs have the potential to alter reproductive health, increase the incidence of cancers, impair immune systems, and delay neural-developmental in children.6 The World Health Organization believes the human health risks of EDCs may be significantly underestimated.7 Known MP effects on marine life and the environment are concerning, but the unknown effects are even more distressing. Many fear we are releasing lethal compounds that could have catastrophic consequences for human health and ecosystems.8

A view from the ground

Typical waste water and sewage water plants were designed for treating large particulate pollutants. As a result, most treatment plants are not equipped to filter and prevent the release of smaller and smaller MP into water environments. As a result, water treatment plants themselves have become major source points for MP in industrialized countries. As populations and economies grow, MP concentrations and pollution levels will increase in step without intervention. 

Moreover, many industrialized nations are unable to cope with even traditional water pollutants. The UK’s water utilities were recently told to clean up their act after reports showed heightened pollution levels in rivers, ground water and drinking water.9 Next to these, micropollutants represent an even bigger challenge. 

Meanwhile, across the Channel, governments are worried about water quality. The EU Commission announced proposed revisions to its outdated drinking water directives which involve higher quality, tighter controls and greater public access to water data.10 Even Switzerland, with arguably the world’s highest water quality, carried out a study between 2006-2010 that resulted in regulatory changes and investments in MP removal technologies.11

Emerging Markets—Sinking further and faster

As industrialization expands to developing economies—already grappling with water shortages and water pollution—the outlook is worsening by the metric volume. According to Global Risk Insights, more than 90% of China’s underground aquifers, supplying the country’s drinking water, are polluted. India—another high growth country—shares a similar gloomy outlook.12

…more than 90% of China’s underground aquifers, supplying the country’s drinking water, are polluted.

Long-term trends like population growth, urbanization, and industrialization ensure that water shortages in emerging markets will persist. Treated wastewater is already an important strategy for reducing water stress in emerging markets. But as in developed markets, current MP loads in wastewater will only add to water toxicity if investments in the right technologies are not made.

The regulatory solution

Given their ubiquitous use and obvious benefits for health, business and society, MP bans are not politically or economically viable. MP in the form of fertilizers, herbicides and other organic materials provide valuable protection for crops and livestock that ensures food for billions. Similarly, banning certain MP would deny life-saving drugs and wellness-enhancing products to billions of patients and consumers worldwide. Moreover, the regulatory hurdles are notoriously difficult and the process long and convoluted. Recall the recent failed attempt to ban the now infamous micropollutant, glyphosate. 13

Advanced Solutions to reduce micro-pollution

We invest in the companies that ensure our water cycle flows smoothly so that society can function optimally and planetary life can flourish abundantly.

A better approach is to reduce MP and prevent their entry into natural and municipal waterways at their source points (i.e. wastewater treatment plants). Fortunately, water treatment technologies have advanced over the past decade and a number of alternatives are available including: reverse osmosis (RO), advanced oxidation (ozonation), membrane bioreactors, powdered activated carbon adsorption (PAC), and ultraviolet disinfection (UV).

Of these, scientific and industry studies confirm and favor, PAC and ozonation as the most cost-effective and technologically-feasible technologies for the job.14

In the short-turn, additional investments to upgrade existing water infrastructure will incur costs.  However, maintenance upgrades to current systems even in the absence of MP would also be necessary while far less effective at reducing the toxicity of effluent. Seen in this way, investments in MP reduction technologies like ozonation and PAC are extremely cost-efficient. 

In contrast, the cost of inaction for life under the sea and life on land may be too high to ignore.

1 Micropollutants in Wastewater: Fate and Removal Pro cesses, S. Das, N.Mitra Ray et al., Chapter from bo ok, Physico- Chemical Wastewater Treatment and Resource Recovery
For a comprehensive listing of registered chemical substances within the EU ormation- on-chemicals/registered-substances
US National Toxicology Program, US Department of Health and Human Services,
Reducing the Discharge of Micropollutants in the Aquatic Environment: The Benefits of Upgrading Wastewater Treatment Plants, Environmental Science & Technolog y, 2014, 48, 7683-7689
5 Antibiotic waste is polluting India and China’s rivers; big pharma must act, October 25, 2016
Report on the State of Science of Endocrine Disrupt ing Chemicals 2012, World Health Organization
7 Ibid, p. 22
8 UN Environment Programme (UNEP), Global Chemi cals Outlook: Towards sound management of chemicals , 2012
9 Water companies warned on failure to reduce p ollution incidents, Financial Times, February 19, 2 018
10 Available at water-drink/review_en.html
Reducing the Discharge of Micropollutants in t he Aquatic Environment: The Benefits of Upgrading W astewater Treatment Plants, Environmental Science & Technolog y, 2014, 48, 7685-86
Water Wars: China’s new weapon against India, S eptember 26, 2017, Global Risk Insights
13 Glyphosate, Top-selling Weed Killer, Wins EU Approval for 5 years, New York Times, November 27, 2017
Reducing the Discharge of Micropollutants in the Aquatic Environment: The Benefits of Upgrading Wastewater Treatment Plants, Environmental Science & Technolog y, 2014, 48, 7686


Disclaimer RobecoSAM

The information contained on these pages is solely intended for Qualified Investors in accordance with the Swiss Collective Investment Schemes Act of 23 June 2006 (“CISA”) domiciled in Switzerland, Professional Clients in accordance with Annex II of the Markets in Financial Instruments Directive II (“MiFID II”) domiciled in Liechtenstein, Austria, Germany, Sweden, UK, France, Netherlands or Italy holding a distributor license or herewith requesting respective information on products and services in their capacity as Professional Clients.
Some funds about which information is shown on these pages fall outside the scope of the Swiss Collective Investment Schemes Act of 26 June 2006 (“CISA”) and therefore do not (need to) have a license from or registration with the Swiss Financial Market Supervisory Authority (FINMA). Some funds about which information is shown on this website may not be available in your domicile country.
To view the Robeco/RobecoSAM products that are registered/available in your country, please go to the respective Fund Selector and select your country of domicile. Neither information nor any opinion expressed on this website constitutes a solicitation, an offer or a recommendation to buy, sell or dispose of any investment, to engage in any other transaction or to provide any investment advice or service. An investment in a Robeco or RobecoSAM product should only be made after reading the related legal documents such as management regulations, prospectuses, annual and semi-annual reports, which can all be obtained free of charge at the Robeco offices in each country where Robeco has a presence.

By clicking “I agree” you confirm that you/the company you represent falls under one of the above-mentioned categories of addressees and that you have read, understood and accept the terms of use for this website.