The Hindu Editorial

Editorial 1: India is running out of phosphorus; does the answer lie in our sewage?

Introduction

The problem with the fertilisation of land is as old as agriculture itself. When early humans first began to engage in settled agriculture, they quickly realised that while crops require nutrients for their growth, repeated cycles of cultivation and harvest depleted these nutrients, reducing yield over time.

The change in practices

This observation led to practices to restore essential nutrients in the soil necessary for plant and crop growth.
Indigenous communities around the world developed methods of fertilisation, for example, using fish remnants and bird droppings (guano) as fertilisers.
This changed in the 19th century, which saw significant advancements in chemistry, leading to the creation of synthetic fertilisers as well as the identification of nitrogen, phosphorus, and potassium.
The Green Revolution of the mid-20th century accelerated the adoption of high-yield crop varieties and intensive use of these fertilisers, and today these substances are crucial to sustain global food production.

The issues with Phosphorus

Phosphorus is scarce and exists only in limited quantities, in certain geological formations.
Not only are we running out of it, it also pollutes the environment.
It doesn’t exist as a gas, which means it can only move from land to water, where it leads to algal blooms and eutrophication.

Geopolitics and phosphorus

The history of phosphorus spans its discovery in guano to current global supply chains.
The world’s largest reserves are in Morocco and the Western Sahara region.
But here, phosphorus coexists with cadmium, a heavy metal that can accumulate in animal and human kidneys when ingested.
Removing cadmium is also an expensive process.
As a result, cadmium-laden fertilisers are often applied to the soil, absorbed by crops, and consumed, bioaccumulating in our bodies.
Studies have found that this accelerates heart disease.
Only six countries have substantial cadmium-free phosphorous reserves.
Of them, China restricted exports in 2020 and many EU countries no longer buy from Russia. So the market for safe phosphorus has suddenly exploded.
This is one reason why Sri Lanka banned the import of synthetic fertilisers and went organic in 2021, later experiencing a sudden drop in crop yield that precipitated a political crisis.
Today, India is the world’s largest importer of phosphorus, most of it from the cadmium-laden deposits of West Africa.
Not all crops absorb cadmium at the same rate, but paddy, a staple crop in India, is particularly susceptible; Indian farmers also apply a lot of fertilisers to paddy.
Other grains, such as wheat, barley, and maize also absorb cadmium, just less.

The phosphorus disposal problem

First, only about a fifth of the phosphorus mined is actually consumed through food. Much of it is lost directly to water bodies as agricultural run-off, due to the excessive application of fertilisers.
Second, most of the phosphorus that people consume ends up in the sewage. Most sewage in India is still not treated or treated only up to the secondary level.
So even if the organic matter is digested, the effluent discharged from STPs still contains nitrates and phosphates.
Of these, nitrates can be digested by denitrifying bacteria and released safely as nitrogen gas into the atmosphere, while phosphorus remains trapped in the sediments and water column.
It is then absorbed by the algal blooms that grow in response to the high nutrient supply, and when they decompose, the bacteria that feed on them consume the dissolved oxygen.
The result: water bodies become oxygen-starved, leading to fish deaths. The algal blooms are also toxic, causing respiratory issues, nausea, and other ailments to people exposed to them.

Finding phosphorus elsewhere

Since much of the phosphorus is not actually taken up by crops, one way to ameliorate the phosphorus paucity is to reduce the use of chemical fertilisers through precision agriculture.
Low-input agro-ecological approaches are increasingly proving to be a viable alternative.
But there is increasing interest in closing the phosphorous loop by mining urban sewage to produce high quality phosphorus.
Interest in ‘circular water economies’ has in fact prompted the European Union – which has almost no phosphorus reserves of its own – to rethink the urban water cycle.
First, source separating toilets – almost two thirds of the phosphorus we consume leaves in our urine and the rest in faeces.
Urine also contains large amounts of nitrogen and potassium. If we can collect this safe and concentrated waste stream, we could generate a local fertiliser source.
Second, recycling wastewater and sludge – Sewage recycling already occurs in some form in India today.

Way forward

The best way is to create a circular water economy. If the technology is cheap enough, can we give a concession to set up STPs with phosphorus mining plants and allow them to sell the fertiliser.
And such changes, India can become less dependent on uncertain geopolitical crises; farmers can procure fertilisers at affordable rates; water bodies will have some hope of becoming swimmable and public health can gain from the consumption of food grown in cadmium-free soils.

Editorial 2: With climate change, tackling new disease scenarios

Context

In its latest report released this March, the Intergovernmental Panel on Climate Change (IPCC) delivers a stark warning: climate change heightens the global risk of infectious diseases.

Climate change, more infections

Habitat loss forces disease-carrying animals to encroach upon human territory, increasing the risk of human-animal interaction and the transfer of pathogens from wildlife to humans.
Viruses which do not harm animals can be fatal for humans.
Nipah virus, which has been causing outbreaks in Kerala for many years now, is a good example.
Over half of all-known infectious diseases threatening humans worsen with changing climate patterns.
Diseases often find new transmission routes, including environmental sources, medical tourism, and contaminated food and water from once-reliable sources.
This dynamic introduces invasive species and extends the range of existing life forms.
Both these trigger upheavals in ecosystems that are complex and confound ecologists and epidemiologists to predict outbreaks.
Human-induced climate change is unleashing an unprecedented health vulnerability crisis.
India, in particular, has felt the ominous impact, with early summers and erratic monsoons causing water scarcity across the Gangetic plains and Kerala.
These climatic shifts are manifesting in severe health crises, including a dengue epidemic in Dhaka (Bangladesh) and Kolkata and the Nipah outbreak in Kerala.

Surveillance and reporting

Changed disease scenarios require a revision of strategies to detect and deal with them.
The Integrated Disease Surveillance Programme (IDSP) was rolled out in a few States in 2007.
From reporting 553 outbreaks in 2008, it last reported 1,714 in 2017.
It was phased out in favour of a new, a web-enabled, near-real-time electronic information system called Integrated Health Information Platform (IHIP).
The current design of surveillance is not adequate for the emerging disease scenario.
Mitigating the spread of climate change-induced diseases requires safeguarding ecosystems, curbing greenhouse gas emissions, and implementing active pathogen surveillance.
A unified approach, termed One Health which integrates monitoring human, animal, plant, and environmental health, recognises this interconnectedness.
This approach is pivotal in preventing outbreaks, especially those that originate from animals.
It encompasses zoonotic diseases, neglected tropical diseases, vector-borne diseases, antimicrobial resistance, and environmental contamination.
India must launch One Health and infectious disease control programmes by building greater synergies between the Centre and States and their varied specialised agencies.
Animal husbandry, forest and wildlife, municipal corporations, and public health departments need to converge and set up robust surveillance systems.
More importantly, they will need to build trust and confidence, share data, and devise logical lines of responsibility and work with a coordinating agency.
So far, the Office of the Principal Scientific Adviser to the Prime Minister has been taking this lead but with new World Bank and other large funding in place, this will need greater coordination and management.

‘Disease x’ and beyond

Globally, there is an obsession with the enigmatic “disease X,” but it is the familiar annual cycles of known agents such as influenza, measles, Japanese encephalitis, dengue, diarrhoea among others that will continue to test the public health system.
Climate change is not limited to infectious diseases. It also exacerbates injuries and deaths from extreme weather events, respiratory and cardiovascular diseases, and mental health issues.

Conclusion

The re-emergence of Nipah in Kerala is a wake-up call, that mere biomedical response to diseases is inadequate. In the face of a changing climate and the growing threat of infectious diseases, protecting ecosystems, fostering collaboration, and embracing the One Health paradigm are our best defences.

27 Sep 2023 : The Hindu Editorial