Which one of the following is not correct with regard to the harmful effects of particulate matter of the size 2.5 micro meters or less?

Options

A. It can be inhaled into the lungs
B. It can cause respiratory problems
C. It can directly enter into our ciculatory system
D. It can cause inflammation and damage to the lungs

Answer

To solve the question regarding the harmful effects of particulate matter of size 2.5 micrometers or less, we will analyze the provided options step by step.

### Step 1: Understand Particulate Matter (PM2.5)
Particulate matter (PM2.5) refers to tiny particles or droplets in the air that are 2.5 micrometers or smaller. Due to their small size, they can penetrate deep into the lungs and even enter the bloodstream, leading to various health issues.

**Hint:** Remember that PM2.5 is particularly harmful because of its size, allowing it to reach the lungs and potentially the circulatory system.

### Step 2: Analyze the Options
We need to determine which statement about PM2.5 is NOT correct. The options typically include statements about its effects on health.

1. **It can be inhaled into the lungs.**
- This statement is correct. PM2.5 can indeed be inhaled and can cause damage to the lungs.

2. **It can cause respiratory problems.**
- This statement is also correct. Inhaling PM2.5 can lead to respiratory issues such as asthma, bronchitis, and other lung diseases.

3. **It can directly enter into our circulatory system.**
- This statement is NOT correct. While PM2.5 can have systemic effects, it primarily affects the respiratory system first. It does not directly enter the circulatory system without first impacting the lungs.

4. **It can cause inflammation and damage to the lungs.**
- This statement is correct. PM2.5 is known to cause inflammation and damage to lung tissues.

**Hint:** Focus on the effects of PM2.5 on the body and how it interacts with different systems.

### Step 3: Identify the Incorrect Statement
From our analysis, the statement that is NOT correct is: **"It can directly enter into our circulatory system."** This is the answer we are looking for, as PM2.5 primarily affects the respiratory system before any potential systemic effects.

### Conclusion
The answer to the question is that the statement **"It can directly enter into our circulatory system"** is NOT correct regarding the harmful effects of particulate matter of size 2.5 micrometers or less.

**Final Answer:** It can directly enter into our circulatory system.