A disease associated with prolonged exposure to silica dust during glass production, characterized by classic X-ray findings of calcified lymph nodes and pleural involvement, is most likely what disease?
Q242
Which of the following statements about N95 masks is true?
Q243
Occupational cancer involves the following organs, except:
Q244
A 45-year-old man presents with a dry cough, fatigue, and bilateral hilar lymphadenopathy on chest X-ray. What is the most likely diagnosis?
Occupational Health Indian Medical PG Practice Questions and MCQs
Question 241: A disease associated with prolonged exposure to silica dust during glass production, characterized by classic X-ray findings of calcified lymph nodes and pleural involvement, is most likely what disease?
A. Byssinosis
B. Berylliosis
C. Silicosis (Correct Answer)
D. Anthracosis
Explanation: ***Silicosis*** [1][2]
- Prolonged exposure to **silica dust** during glass production leads to characteristic **X-ray findings** of calcified lymph nodes and an "eggshell" pattern.
- Associated with **pleural involvement** resulting in fibrous plaques and a greater risk of developing **tuberculosis** [3].
*Anthracosis* [2]
- Caused by exposure to **coal dust**, not silica, and primarily affects the **upper lobes** of the lungs.
- X-ray findings do not show the classic "eggshell" pattern; they are primarily concerned with **black lung disease** changes.
*Berylliosis* [2]
- Results from exposure to **beryllium dust**, typically presenting with **granulomatous lung disease** rather than an eggshell pattern.
- Less common and does not show significant pleural changes as seen in silicosis.
*Byssinosis*
- Associated with the inhalation of **cotton dust**, leading to respiratory issues, but lacks the calcified nodules characteristic of silicosis.
- Symptoms often improve over a weekend, differentiating it from silicosis.
**References:**
[1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, p. 697.
[2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, p. 695.
[3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 697-698.
Question 242: Which of the following statements about N95 masks is true?
A. They were designed for occupational safety against various airborne particles. (Correct Answer)
B. It filters 95% of particles 0.3 microns and larger.
C. They are only effective against particles larger than 1 micron.
D. N stands for 'Not oil-resistant'.
Explanation: ***They were designed for occupational safety against various airborne particles.***
- **N95 masks** are certified by NIOSH (National Institute for Occupational Safety and Health) for use in occupational settings to protect against various airborne hazards.
- Their primary purpose is to filter at least **95% of airborne particles ≥0.3 microns**, making them crucial for protecting healthcare workers and others in environments with airborne contaminants.
*N stands for 'Not oil-resistant'.*
- This statement is **technically correct but commonly misunderstood**; the **"N" designation means "Not oil-resistant"**, indicating the mask should not be used in environments containing oil-based aerosols.
- N95 masks are suitable for solid and water-based aerosols but not for oil-based particles, which require R (oil-Resistant) or P (oil-Proof) rated respirators.
*It filters 95% of particles 0.3 microns and larger.*
- This statement is **technically accurate but incomplete** as the correct answer; **N95 masks filter at least 95% of airborne particles ≥0.3 microns** in size.
- The **0.3-micron particle size** is used as the standard for testing because it represents the most penetrating particle size (MPPS), making it the most challenging for filters to capture.
- However, the key distinction is that this is just a **technical specification**, whereas the correct answer emphasizes the **primary design purpose** of occupational safety.
*They are only effective against particles larger than 1 micron.*
- This statement is incorrect as N95 masks are designed to filter particles as small as **0.3 microns** with **at least 95% efficiency**.
- Their effectiveness extends to particles significantly smaller than 1 micron, which is why they are effective against many **viruses and bacteria**.
Question 243: Occupational cancer involves the following organs, except:
A. Bladder
B. Liver
C. Breast (Correct Answer)
D. Lung
Explanation: ***Breast***
- While breast cancer is a significant health concern, it is not consistently recognized as a primary site for **occupational cancer** directly linked to specific workplace exposures.
- The major risk factors for breast cancer are typically **hormonal**, **genetic**, and related to **lifestyle**, rather than occupational carcinogens.
*Lung*
- The **lung** is a well-established site for occupational cancer, commonly associated with exposure to carcinogens like **asbestos**, **radon**, **silica**, and **polycyclic aromatic hydrocarbons (PAHs)**.
- Industries such as mining, construction, and manufacturing have a higher risk of lung cancer due to inhaled occupational hazards.
*Bladder*
- The **bladder** is a recognized site for occupational cancer, particularly for workers exposed to **aromatic amines** and **benzidine-based dyes**.
- Occupations in the chemical, rubber, and dye industries have historically shown increased rates of bladder cancer.
*Liver*
- The **liver** can be affected by occupational carcinogens such as **vinyl chloride** (leading to angiosarcoma of the liver) and **arsenic**.
- Workers in plastics manufacturing and those exposed to certain industrial chemicals are at higher risk for liver cancers.
Question 244: A 45-year-old man presents with a dry cough, fatigue, and bilateral hilar lymphadenopathy on chest X-ray. What is the most likely diagnosis?
A. Silicosis
B. Sarcoidosis (Correct Answer)
C. Tuberculosis
D. Asbestosis
Explanation: ***Silicosis***
- The patient's **occupation in a mine** suggests exposure to **silica dust**, leading to lung diseases including silicosis [1].
- **Bilateral hilar lymphadenopathy** and dry cough are common findings, aligning well with the symptoms presented.
*Tuberculosis*
- Typically presents with **cough**, but more often with **hemoptysis** and systemic symptoms like **weight loss** and **night sweats**.
- **Hilar lymphadenopathy** may be present, but not as clearly related to mining exposure as in silicosis. Notably, silicosis is associated with increased susceptibility to tuberculosis [1].
*Sarcoidosis*
- Can cause **bilateral hilar lymphadenopathy** [2], but often presents with additional systemic symptoms and is less directly connected to occupational exposure to dust.
- Frequently associated with **skin lesions** and **uveitis**, which are not mentioned in this case.
*Asbestosis*
- Primarily associated with **exposure to asbestos**, typically causing symptoms like **dyspnea** and **pulmonary fibrosis**, rather than hilar lymphadenopathy.
- The occupational history does not support asbestosis, as mining exposure is more indicative of silicosis.
**References:**
[1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 697-698.
[2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 700-701.
