UV-rays:

Ultraviolet light, a type of electromagnetic radiation, has a wavelength between 10 and 400 nm.
It is shorter than visible light but longer than X-rays.
These can be found in sunlight and makeup 10% of the sun’s overall light output.
Explanation:

UV-ray effect on humans:

Uv rays cause Skin cancer (melanoma and non-melanoma).
Premature ageing and other skin damage are also caused by UV rays.
Cataracts and other eye damage also result from UV rays.
It damages Immune system suppression.
UV-rays on the environment:

Both people and animals are affected by ultraviolet radiation.
Almost all green plants have their growth processes slowed down by too much UV-B radiation.
There are worries that the loss of plant species and decreased global food supply could result from ozone depletion.
Thus,

(i) damage to the immune system- Correct.

(ii) damage to lungs- Incorrect.

(iii) skin cancer- Correct.

(iv) peptic ulcers- Incorrect. Additional InformationPeptic ulcer:

An ulcer on the lining of people’s stomach, small intestine, or oesophagus is referred to as a peptic ulcer.
The bacteria Helicobacter pylori infection and long-term use of nonsteroidal anti-inflammatory drugs are the two main causes of peptic ulcers.
Damage lung:

The term “lung disease” covers a wide range of conditions that affect the lungs, including COPD, pneumonia, tuberculosis infections, lung cancer, and other breathing issues.
Respiratory failure can result from specific lung conditions.