Water pollution is a major problem caused by human activities like industrial chemical pollution and oil spills that contaminate water supplies and disrupt ecosystems and food chains. Only a small percentage of Poland's water sources are clean enough for drinking or industrial use due to severe pollution in many rivers and lakes. The main sources of water in Tenerife are dew collected by pine trees, rain, and melted snow that pass into underground reservoirs, though around 42% of the water is contaminated.

2. Water pollution is a contamination of water tanks.
Mostly it is due to human activities like chemical
pollution from industries, cistern’s collisions or oil
leakage into the water. It’s bad because of ruining
animal’s life who live in polluted water. It also
disrupts a food chain.
People try to stop water pollution by building sewage
treatment plants.

3. Only 4% of Poland's rivers and lakes contain water clean
enough to drink. Over 30% of the rivers in our country is
so polluted, that their waters cannot be even used for
industrial purposes. The two-thirds of wells in Polish
villages are undrinkable.

4. Main sources of water in Tenerife are:
- the dew collected by pine trees at night,
- the rain from clouds that cover the mountains
- the melting snow during the winter months.
All these kinds of water pass into the ground via the roots of the pine
trees, where it sits in the natural underground reservoirs.
Water contamination in Tenerife is something around 42%.