Discover STEM - Petrosains, The Discovery Centre

How Does Polluted Water Affect Plants?

Water pollution has a wide variety of effects on plant life and the environment in general.

Pollution in water not only harms plant growth but also allows plants to absorb dangerous chemicals from the water and pass them on to animals that rely on them for survival.

Plants also pass on these pollutants to humans who consume them.

Did you know that we eat water?

We do! Water can be found inside the crops that we grow for food.

What happens if the water we use on our crops is polluted?

In this activity, you will see how pollution can easily get into our water, our food and our body.

What do we need?

A clear glass (350ml)

Tap water (150ml)

A stick of fresh celery with the leaves still on it

A knife

Red or blue food colouring

What to do?


Fill the glass with tap water. Add two or three drops of food colouring. Wash the piece of celery. Leave the leaves on.


Being very careful, use the knife and cut off the bottom of the celery.


Put the celery in the glass filled with coloured water.


Let the celery stalk sit there for at least three or four hours; you can even leave it overnight.


When the time has passed, take the celery stalk out of the water.


Use the knife (remember to get help from your parents or teacher) and cut a slice off the bottom of the stalk. Observe what happens to the bottom of the stalk.

What Actually Happened?

After 3 hours, the food dye moves up the celery, and it remains in the leaves.

Tiny tubes inside the stem called the xylem. They draw the water up from the roots like a straw by a process called Capillary Action.

Water moves from the roots to the rest of the plant.

Gradually, capillary action lets water climb up to all the different parts of a plant through the xylem tubes in the stem.

How Does Water Pollution Affect Plant Growth?

In nature, the water moves into a plant that brings its nutrients from the soil. Metals and solvents from industrial work can pollute rivers, lakes and water quality. These chemicals can help a plant live, but sometimes they make the plant sick as well.

Plants pull water up to their leaves through their veins. If the water is polluted, the pollution will move up through the plant with the water. As a result, the plant will be polluted. Anything eating the plant will ingest the pollution into their bodies.

Many forms of pollution are odourless and colourless. As a result, we cannot tell they are polluted by looking at them.

PETRONAS Strategy in Mitigating Impacts of Operations to Water Resources

Due to the ability of crops to absorb pollution, it will be a devastating effect on people and animals. Polluted water is unsuitable for drinking, recreation, agriculture, and industry. Hence, the industries must make sure to have a good practise of managing the waste wisely.

Did you know that PETRONAS guidelines use water more efficiently, and better manage effluents across their operations? Water risk assessment methodology encourages proactive control measures to address potential concerns, such as emerging regulations on freshwater and water stress analysis.

PETRONAS strives to reduce, reuse, recycle and recover waste by minimising waster generation at the front-end design and engineering stages as well as to strengthen internal processes and capabilities in waste identification, characterisation, handling and disposal.