Feeding the soil, poisoning health and environment

---

by Sadia Gulzar

---

Fertilisers play vital role in enhancing crop yield. These are used widely around the world to provide crops with the nutrients needed for their efficient growth and producing higher yields. But they also affect biodiversity, human health, water, soil and environment.

While fertilizers serve the vital function of replenishing essential nutrients like nitrogen, phosphorus, and potassium in the soil, which are crucial for plant health, their misuse carries significant risks.

There are two types of fertilisers: synthetic and organic. Synthetic fertilisers, produced through industrial processes, offer quick nutrient delivery. However, they contribute significantly to soil degradation, water pollution and greenhouse gas emissions.

Organic fertilisers, such as compost, manure, and biofertilisers, provide a more sustainable alternative by improving soil health. They play a crucial role in regenerative agriculture and reducing reliance on chemical inputs.

Primarily, fertilizers are composed of nitrogen, phosphorus and potassium. Fertilizers, formed from phosphorus and potassium are obtained from mineral as compared to the one produced from fossil gas-based nitrogen. Initially, nitrogen was used in explosives for military such as TNT (Trinitrotoluene). After World War 2, companies started using it for civilian purposes such as fertilisers.

In Pakistan, the first nitrogenous fertiliser plant — Pak-American Fertilisers Limited– was built in 1958 during the military dictator Ayub Khan’s so-called ‘Green Revolution. It increased food production but also led to worsening income inequality and severe environmental degradation. The new high-yielding variety seeds and fertilisers were expensive and primarily accessible to a few large landowners. The concentration of wealth among a few “22 families” and the growing social and regional inequalities fuelled widespread political discontent.

The overuse of chemical fertilizers and pesticides, combined with intensive irrigation, led to the deterioration of soil quality, nutrient depletion, and increased salinity, adversely impacting long-term agricultural sustainability.

The country has currently 10 fertilizer companies, ranking as the eighth-largest consumer of fertilizers globally. It consumes approximately 6.5 million tons fertilizers annually. To meet the growing demand, Pakistan spends Rs42.339 billion on fertilizers’ imports. The government has allocated Rs30 billion in subsidies for 2024.

A study conducted in 2023 to investigate radioactivity in fertilizers revealed significant radioactivity levels. Samples collected from 15 areas were analysed found high concentration of radionuclides — Radium-226 (Ra-226), Thorium-232 (Th-232), and potassium-40 (K-40). The concentration of Th-232 ranged from 2.586 to 129.05 Bq/kg, while Ra-226 from 1.538 to 76.621 Bq/kg. Notably, K-40 exhibited the widest range from 36.52 to 3,694.23 Bq/kg. These results indicate a continuous decay of radioactive elements within fertilizer products. Furthermore, the study indicated that Sulphate of Potash (SOP), Muriate of Potash (MOP), and Nitro Sulphate contained higher than safety limit radionuclides.

Excessive use of fertilisers in Gilgit-Baltistan

Like many regions of Pakistan, approximately 90% of Gilgit-Baltistan’s population depends on farming and livestock for livelihood. Local farmers have gradually begun using chemical fertilizers and pesticides during the last five decades to increase their agricultural yields.

However, over the past several years, the excessive use of chemical fertilisers in Gilgit-Baltistan has become a growing concern. These fertilisers are heavily applied to boost crops, vegetables and fruit production.

A particularly alarming practice is the consumption of unwashed vegetables, such as carrots, lettuce, and turnips, directly from gardens, especially by children, risking their health. Unfortunately, there is little official data on fertiliser usage or its health impacts in Gilgit-Baltistan.

Also read: Gilgit-Baltistan: smoking, vaping pose a growing health emergency

Disasters in Gilgit-Baltistan: surge in waterborne diseases

Cardiovascular disease — a growing health crisis in Gilgit-Baltistan

One relevant study was conducted in 2020 by the Department of Mathematical Sciences at the Karakoram International University in the Ghizer District’s Yasin Valley off 167 kilometers Gilgit city to determine maximum profit from three key crops: wheat, maize, and alfalfa. According to the findings, wheat cultivation required an average of 28 bags of fertilizer per season, maize about 25 bags, and alfalfa between 32 and 36 bags.

Chemical fertilizers pose serious health risks

The compilation of reports by the US National Institute of Health (NIH) estimated that in the last 100 years, the compounds of the nitrogen in soil, water and air has doubled which not only harmed human but also destroyed biodiversity, plants and animals. We use chemical fertilizers for increasing yield of crops unaware of their adverse health impacts.

Studies conducted during the last over 40 years (1981 to 2020) globally. One-fifth of participants recruited before 1980s and one-fourth during 2000s found. Among them 407 associations found 23% of organ tumors and 16% of hematological malignancies (cancer of blood cells). The studies also found 12% neurological disease, 9% infections, 32% respiratory and 15% skin lesions.

The NIH collected 65 publications across the globe up to 2024 to study the exposure of fertilizers and affect on human. Out of them, 46 publications assessed exposure to inorganic fertilizers from 1969 to 1989 detected a total of 4,565 cases of congenital disorders among 1,92,417 farmers; 275 rheumatoid arthritis cases identified in spouses, using fertilizers. In 17 studies solid tumors were investigated due to exposure of inorganic fertilizers. Among them, two studies revealed maternal exposure to fertilizers, the chance of having Central Nervous System tumor under age 5 children is 1.8 times more in mothers expose to fertilizers then the mother who are not expose to fertilizers.

The study of radionuclides in fertilizers also revealed, radioactive play immense role in rising cancer cases. Though the usage of fertilizers in crops can increase the cultivation despite elevate the Natural Radioactive Nuclides, particularly Potassium Sulphate, Nitro Phosphate Potash (NPK), Ammonium Super Sulphate with higher concentration of Radium, Thorium and potassium radioactive. The high amount of potassium in these radioactive can lead to cancer at different ages. Moreover The prolonged exposure to fertilizers washed in water cause 20% risk of methemoglobinemia, 15 to 25% risk of gastric and cause colorectal cancer.

According to US Environmental Protection Agency, compounds of fertilizers especially Nitrates contaminate the drinking water in irrigated areas and these compounds can cause shortness of breathing, blue tinted skin, condition known as Blue Baby Syndrome.

Fertilizers and environmental challenges

The overuse and mismanagement of fertilizers have led to significant environmental challenges. According to reports, nitrogen losses from farms upstream have caused up to $2.4 billion damage to Gulf fisheries and marine habitats every year since 1980. In addition the fertilizer industry is responsible for the 5% of global heat trapping emission as according to estimation.

Scientist also find out, the manufacturing of fertilizers in industries need higher energy, along with ammonia, which release more Carbon dioxide than any other industrial chemical. Many heat trapping compounds which are more potent then Co2 are formed as a result of fertilizer production. Nitrous Oxides(N2O) is 265 times and methane is 28 time more powerful than carbon dioxide.

According to further reports of 2000 to 2023, in various regions the concentration of nitrate has exceeded recommended safety limit by 30% to 50%. These compounds mix with water and lead to marine death and human health challenges. In a report published in Dawn in 2022, Dr Mehrunisa, Chairperson of Soil Science Department stated, 95% of food came from soil, using inorganic fertilizers.

Over-reliance on synthetic fertilisers can degrade soil health. Excessive application often leads to soil acidification and reduces organic matter, making soils less fertile. For example, continuous use of nitrogen-based fertilisers can cause nutrient imbalances, which not only impact crop yields but also reduce the soil’s ability to retain water and nutrients naturally.

Nutrients from fertilisers, particularly nitrogen and phosphorus, often leach into nearby rivers, lakes, and oceans through runoff. This leads to a process called eutrophication, where excess nutrients trigger rapid algae growth. The resulting algal blooms block sunlight and deplete oxygen in the water, creating “dead zones” where aquatic life cannot survive.

Greenhouse gas emissions

Fertiliser use is a major contributor to climate change. The production of synthetic fertilisers is energy-intensive, relying heavily on fossil fuels. Additionally, when nitrogen-based fertilisers are applied to soil, they release nitrous oxide (N₂O) – a greenhouse gas nearly 300 times more potent than carbon dioxide. The IPCC estimates that nitrous oxide emissions from fertilisers account for around 5% of global greenhouse gas emissions.

Fertiliser run off doesn’t just affect water systems. It also disrupts ecosystems on land and at sea. Excess nutrients favour certain fast-growing species, often at the expense of native plants and animals. For example, in coastal areas, nitrogen pollution can disrupt marine ecosystems, impacting fish populations and local biodiversity. On land, fertilisers can alter the natural composition of grasslands and forests, leading to a decline in plant and animal diversity.

The global reliance on fertilisers

Fertilisers’ demand globally is staggering. Each year, millions of tonnes of nitrogen, phosphorus, and potassium fertilisers are applied to fields across the world, enabling higher crop yields to sustain a growing population. However, this reliance has significant environmental and socio-economic consequences.

Countries with intensive agricultural practices account for the majority of fertiliser use. For example, nitrogen fertiliser consumption has more than doubled in the past 50 years, driven by industrial farming and the need for higher yields. Excess nutrients leach into water systems, nitrous oxide emissions worsen climate change, and long-term soil degradation threatens future agricultural productivity.

Solutions and alternatives

Developed nations, having recognised the major challenges posed by fertilizer use, have begun debating and formulating policies to address them. In contrast, developing countries such as Pakistan, hampered by a lack of policy and weak regulatory mechanisms, remain largely unconcerned about the consequences of excessive and unchecked fertilizer application.

Innovations and sustainable practices should be adopted as alternatives to traditional fertilisers to reduce fertiliser-related environmental impacts while maintaining food production. Technologies like soil sensors, GPS mapping, and data analytics allow farmers to apply fertilisers exactly where and in the quantities they are needed. This minimises waste, reduces runoff, and lowers costs.

To discourage overusage, growers can combine organic sources with the chemical fertilisers to improve soil health and reduce dependency on synthetic fertilizers. Secondly soil testing should be done to identify specific fertilizers for specific soil.