Pollution and Its Health Effects

Pollution and Routes of Exposure

Routes of Exposure

• Establishing the exact toxicity of pollutants is complex due to multiple routes through which humans can be exposed.

• Exposure to pollutants can occur through:

  • Ingestion

  • Inhalation

  • Absorption through the skin

Specific Pollutants and Their Sources

• Example of pollutants include:

  • Lead from water pipes and paint chips

  • Biomass combustion products

• These pollutants can lead to significant health issues when entered into the human body.

Synergism

• Definition: Synergism refers to the interaction of two or more substances that results in an effect greater than the sum of their individual effects.

• Example scenarios illustrating synergism:

  • COVID-19 and Smoking:

  • Smoking can lead to lung damage, compounding the harmful effects of COVID-19, particularly on lung function.

  • Smoking is known to have a carcinogenic effect, exacerbating health risks associated with COVID-19.

  • Asthma:

  • Asthma can be worsened by pollutants, such as smoke from cigarettes, which creates a synergistic effect enhancing respiratory problems.

  • Additional Example:

  • Dysentery:

    • A bacterial infection triggered by contaminated food or water, often due to feces from sewage being released into bodies of water.

    • Results in severe intestinal distress and dehydration, leading to approximately 1.1 million deaths annually, predominantly in developing regions where sanitation is poor and access to clean water is limited.

Ozone (O₃) and Health Effects

• Ozone is a significant pollutant with the following health implications:

  • Causes respiratory conditions such as asthma and other difficulties with lung function.

  • Acts as an irritant on the respiratory tract, causing constriction of the airways and contributing to respiratory illnesses.

  • Additional health symptoms include irritation of the eyes.

• In terms of chemistry:

  • Ozone is a product of the chemical breakdown of nitrogen dioxide (NO₂).

• Importance of Ozone:

  • While ozone is harmful in the troposphere (the lowest layer of Earth's atmosphere), it plays a beneficial role in the stratosphere by filtering harmful ultraviolet (UV) radiation from the sun.

Mesothelioma

• Definition: Mesothelioma is a rare and aggressive cancer primarily caused by exposure to asbestos, a group of naturally occurring fibrous minerals known for their fire-resistant properties.

• This cancer affects the mesothelium, a thin layer of tissue that covers most internal organs, particularly the lungs (pleural mesothelioma), abdomen (peritoneal mesothelioma), and heart (pericardial mesothelioma).

• Risk Factors:

  • Primary risk factor is occupational exposure to asbestos, commonly in industries such as construction, shipbuilding, and manufacturing.

  • Secondary exposure can occur through family members who bring asbestos fibers home on their clothing.

• Symptoms:

  • Symptoms often appear decades after exposure and may include chest pain, persistent cough, shortness of breath, fatigue, and weight loss.

• Diagnosis and Prognosis:

  • Diagnosis involves imaging tests (like X-rays and CT scans) and biopsy to confirm the presence of cancerous cells.

  • Prognosis is often poor due to late diagnosis, with most patients surviving less than one year after diagnosis.