The most common toxins in water supplies and soil

1. Heavy metals

These metals are highly toxic and can accumulate in plants and organisms:

• Lead (Pb) – from old water pipes, industrial waste
• Cadmium (Cd) – from fertilizers (e.g. phosphate fertilizers), mining
• Mercury (Hg) – from industrial emissions, fossil fuels
• Arsenic (As) – from pesticides, mining, geogenic sources
• Chromium (Cr, especially Cr⁶⁺) – from tanneries, industrial waste
• Nickel (Ni) – from metal industry, wastewater

These heavy metals disrupt enzymatic processes in plants and can significantly impair their growth and nutrient uptake .

2. Plant protection products & pesticides

Many pesticides remain in the soil long-term and enter the water:

• Organophosphates (e.g. glyphosate, chlorpyrifos) – affect plants and microorganisms
• Organochlorine compounds (e.g. DDT, Lindane) – extremely persistent, accumulate in plants
• Neonicotinoids – harmful to pollinators, inhibit root formation

These substances can destroy soil microbiology and indirectly harm plants.

3. Nitrates & Phosphates

• Nitrates (NO₃⁻) – from excessive use of fertilizers, leads to groundwater contamination
• Phosphates (PO₄³⁻) – from wastewater and fertilizers, promote algae growth (eutrophication)

Excessive amounts disrupt the balance of nutrient uptake in plants.

4. Salts & soda content (salination)

• Sodium chloride (NaCl) – often a problem in dry regions due to irrigation
• Carbonates/bicarbonates (CO₃²⁻, HCO₃⁻) – increase the pH value, block trace elements
• Sulfates (SO₄²⁻) – from wastewater, can reach toxic concentrations

Result: ionic imbalances, poorer water absorption by plants.

5. Industrial & Organic Pollutants

• Polycyclic aromatic hydrocarbons (PAHs) – from petroleum products, road traffic
• Dioxins & Furans – from waste incineration, extremely persistent
• Pharmaceutical residues (e.g. antibiotics, hormones) – from wastewater, affect plant hormones

These substances influence plant growth by, for example, inhibiting germination or disrupting nutrient uptake.

Which are the most dangerous?

1. Heavy metals (Pb, Cd, Hg, As) → Accumulation in plants & toxic to humans
2. Pesticides (DDT, glyphosate, neonicotinoids) → Long-term damage to ecosystems
3. Nitrates & Phosphates → Water Pollution & Nutrient Imbalance
4. Salts (NaCl, CO₃²⁻) → soil salinization & impaired water absorption

Solutions: Regular soil and water analyses and biological filtration methods.

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