9 a] Explain Occupational health and safety considerations in water and wastewater treatment.
Occupational Health and Safety Considerations at Wastewater Treatment Plants
Sewage Composition:
- Wastewater includes domestic and industrial wastewater, and often stormwater runoff.
- Can carry contaminants like oils, salts, metals, asbestos, pesticides, and herbicides.
Historical Hazards:
- Previously considered highly hazardous, especially due to confined space entry deaths.
- Risks remain, with ongoing health issues and fatalities among workers.
Health Issues:
- Acute Exposures: Short-term exposure leading to eye, nose, or throat irritation.
- Chronic Exposures: Long-term exposure causing organ damage and occupational allergies.
Airborne Exposure:
- Aerosols generated during wastewater treatment contain microbiological and chemical substances.
- Inhalation is a primary route of exposure.
- Open tanks and basins allow for airborne dispersion of volatile organics, some of which are carcinogenic or mutagenic.
Infectious Diseases:
- Workers are at risk of infection from waterborne pathogens.
- Symptoms may include nausea, vomiting, diarrhea, and flu-like complaints.
- New workers are more susceptible to illness compared to experienced workers with immunity.
Chemical Exposure:
- A wide range of chemicals, including solvents, pesticides, PCBs, heavy metals, and more, are present in wastewater and sludge.
- These substances can be inhaled or absorbed through the skin.
Routes of Entry:
- Inhalation: Workers inhale chemicals or organisms near aeration tanks, dewatering processes, or during sludge handling.
- Skin Contact: Chemicals or pathogens can be absorbed through cuts, abrasions, or direct skin contact with wastewater or sludge.
Preventive Measures:
- Use of engineering controls, administrative procedures, and process control strategies.
- Provision of protective equipment to reduce exposure risks.
- Medical surveillance to monitor health and detect occupational diseases early.