Uchafuzi wa mazingira unasababishwa na utupaji holela wa taka.

A natural translation is:

Environmental pollution is caused by indiscriminate dumping of waste.

A more literal breakdown is:

• uchafuzi = pollution / contamination
• wa mazingira = of the environment
• unasababishwa = is caused
• na = by
• utupaji holela wa taka = careless / indiscriminate dumping of waste

Uchafuzi means pollution, contamination, or the act/process of making something dirty.

It is related to -chafu, which means dirty. So the idea is:

• chafu = dirty
• uchafu = dirt / filth
• uchafuzi = pollution / contamination / dirtying

In this sentence, uchafuzi is best understood as pollution.

Here wa is a linker meaning something like of.

So:

• uchafuzi wa mazingira = pollution of the environment

In Swahili, this linker changes form depending on the noun that comes before it. Since uchafuzi is a u- class noun, the connector is wa.

So this is not the separate word wa meaning they are or anything like that. Here it is just the of-linker.

Mazingira usually means:

• environment
• surroundings
• conditions
• circumstances

In this sentence, it clearly means the environment.

A learner may notice that mazingira looks plural, and that is true grammatically, but in everyday use it often functions as the normal word for environment. You do not need to force a singular meaning in English.

Unasababishwa means is caused or is being caused.

A useful way to see it is:

• u- = subject agreement for uchafuzi
• -na- = present tense / ongoing present
• -sababishwa = passive form related to kusababisha, to cause

So the whole word means:

• it is caused
• or more literally, it is being caused

In normal English, is caused is the best translation here.

Because the subject is uchafuzi.

In Swahili, the verb agrees with the noun class of the subject. Since uchafuzi belongs to a u- type noun class, the verb also starts with u- agreement:

• uchafuzi una...

So:

• Uchafuzi unasababishwa... = Pollution is caused...

This agreement is a very important part of Swahili grammar.

It breaks down like this:

• utupaji = dumping / throwing away / disposal
• holela = carelessly / indiscriminately / randomly
• wa taka = of waste / of trash

So:

• utupaji holela wa taka = indiscriminate dumping of waste
• or careless disposal of waste

A learner may also notice that utupaji comes from the verb kutupa, meaning to throw away.

This is the same kind of wa as in uchafuzi wa mazingira: it links two nouns and means of.

So:

• utupaji ... wa taka = dumping ... of waste

Again, the form wa is chosen because it agrees with the noun before it, here utupaji.

So both wa words in the sentence are doing the same basic job: linking nouns.

Because holela describes the dumping, not the waste.

So the structure is:

• utupaji holela = careless / indiscriminate dumping

Swahili usually puts modifiers after the word they describe. Here the meaning is not waste that is careless, but dumping that is careless.

Because this sentence is in the passive voice.

In passive constructions, na often introduces the cause, agent, or means:

• unasababishwa na... = is caused by...

So here:

• na utupaji holela wa taka = by indiscriminate dumping of waste

The word na can mean and, with, or by, depending on context. Here the passive verb makes by the correct choice.

Because Swahili does not normally use articles like English does.

So uchafuzi, mazingira, and taka do not need separate words for:

• a
• an
• the

Context tells you what is meant. In English, we add articles where they sound natural:

• Environmental pollution is caused by indiscriminate dumping of waste
• The pollution of the environment is caused by the careless dumping of waste

Both can fit the Swahili sentence, depending on context.

Yes. A natural active version is:

Utupaji holela wa taka unasababisha uchafuzi wa mazingira.

That means:

Indiscriminate dumping of waste causes environmental pollution.

So the difference is:

• Passive: Uchafuzi wa mazingira unasababishwa na...
• Active: Utupaji holela wa taka unasababisha...

Both are correct; they just focus on different parts of the message.