Mercury and Chromium Pollution Effects

Questions and Answers

What should students do with excess chemicals before leaving the laboratory?

Leave them on the work surfaces

Mix them with other chemicals

Keep them for future experiments

Return them to the appropriate location or dispose of them as instructed (correct)

Which action is NOT part of the teacher's responsibilities after an experiment?

Document unforeseen events to prevent repetition

Ensure work surfaces are left clean and dry

Ensure returned glassware is clean and undamaged

Order new experiments to be prepared immediately (correct)

Which of the following is a measure for accident prevention in the workplace?

Improvement of working environment (correct)

Ignoring occupational risks

Only providing minimal training to staff

Using more dangerous equipment

What is the first step in ensuring safety regarding chemical hazards?

Assess chemical hazards and set priorities Signup and view all the answers

Which of the following actions should NOT be taken when handling chemicals requiring disposal?

Leave them for the next person to manage Signup and view all the answers

What is one of the obligations of employers regarding occupational risks?

To assess risks and take protective actions Signup and view all the answers

When assessing chemical hazards, what is one essential action to take?

Obtain information about their hazards Signup and view all the answers

Which step is critical after identifying chemicals in use?

Gather information regarding their hazards Signup and view all the answers

What is one effective control method for managing hazardous chemicals?

Substitution with less hazardous options Signup and view all the answers

What does the SIN List represent?

Chemicals identified as Substances of Very High Concern Signup and view all the answers

Which of the following best describes the purpose of technical measures in chemical management?

To prevent the transfer of dangerous chemicals and reduce worker exposure Signup and view all the answers

Why is substitution of hazardous chemicals important?

To avoid allergic reactions and other health issues Signup and view all the answers

What kind of information is vital when considering chemical substitutions?

Potential unexpected dangers from new substances and processes Signup and view all the answers

Which of the following is NOT a method mentioned for reducing chemical hazards?

Using powdered substances exclusively Signup and view all the answers

What role do workers play in managing workplace chemical safety?

They can be involved in safety organizations and committees Signup and view all the answers

What change in product form can reduce dust hazards associated with chemicals?

Switching to pellets or paste instead of powders Signup and view all the answers

What are the primary forms of mercury that exist in the environment?

Metallic elements, organic compounds, and inorganic salts Signup and view all the answers

What process do microorganisms perform that affects mercury in aquatic ecosystems?

Methylation transforming mercury into methyl mercury Signup and view all the answers

Which form of chromium is considered more toxic to humans?

Cr(VI) Signup and view all the answers

Which activity is identified as a major source of mercury pollution?

Mining Signup and view all the answers

Why is metal speciation important in understanding environmental toxicity?

It determines the activities of different metal ions. Signup and view all the answers

Which industrial activity is NOT linked to chromium pollution?

Fish farming Signup and view all the answers

What is the consequence of biomagnification in aquatic ecosystems?

Accumulation of toxins in higher trophic levels Signup and view all the answers

Which statement about chromium pollution is accurate?

Industrial wastes contribute to the accumulation of Cr(VI) in soil. Signup and view all the answers

What type of gloves should be selected for protection against sparks and moderate heat?

Leather Gloves Signup and view all the answers

Which material is not effective against alkalis and solvents?

Synthetic Gloves Signup and view all the answers

What type of gloves provides general-purpose hand protection with slip-resistant qualities?

Coated Fabric Gloves Signup and view all the answers

Which gloves are known for cut- and abrasive-resistance while providing warmth?

Synthetic Gloves Signup and view all the answers

What is the main disadvantage of fabric gloves when it comes to heavy materials?

They do not provide enough protection. Signup and view all the answers

Which type of gloves offer reflective and insulating protection against heat?

Aluminized Gloves Signup and view all the answers

Which group of gloves is specifically designed for protecting against dirt and slivers?

Fabric Gloves Signup and view all the answers

What additional features do aramid fiber gloves provide compared to synthetic gloves?

They provide better heat resistance. Signup and view all the answers

What type of fire does Class B specifically refer to?

Flammable or combustible liquids Signup and view all the answers

What is the primary purpose of a fire blanket?

To cover fires on individuals Signup and view all the answers

What design feature is essential for safety cans?

A spring closing lid and spout cover Signup and view all the answers

What is a key requirement for storing flammable liquids?

In flammable storage cabinets Signup and view all the answers

What defines Class D fires?

Combustible materials in laboratories Signup and view all the answers

How does a fire blanket extinguish flames?

By suffocating the fire with air blockage Signup and view all the answers

What is a characteristic of explosion-proof refrigeration equipment?

It is designed for safe storage of volatile materials Signup and view all the answers

What capacity does a safety can typically have?

Not more than 5 gallons Signup and view all the answers

Study Notes

Mercury

Exists in three forms: metallic elements, inorganic salts, and organic compounds.
Each form has varying toxicity and bioavailability.
Present in aquatic environments (lakes, rivers, oceans) where microorganisms convert it into methyl mercury, leading to biomagnification.
Major sources include agriculture, municipal wastewater, mining, incineration, and industrial discharges.

Chromium

Commonly exists as trivalent (Cr+3) and hexavalent (Cr+6) forms, both toxic to living organisms.
Cr(III) is less harmful in groundwater, while Cr(VI) poses significant health risks to humans.
Widely used in industries: metallurgy, electroplating, paints, tanning, wood preservation, chemical production, and pulp/paper production.
Pollution primarily from industrial and agricultural activities, with serious environmental impacts, especially from hexavalent chromium.
Manufacturing processes can lead to soil and water contamination through industrial waste and irrigation practices.

Chemical Safety Measures

Register all chemicals used in workplaces and maintain a chemical inventory.
Involve workers in safety organizations like Safety Committees for better involvement in safety protocols.

Technical Measures

Aim to prevent chemical hazards at their source and reduce worker exposure.
Substitution of hazardous chemicals with less dangerous alternatives is effective for safety.
Examples include using water-based paints instead of solvent-based or replacing powdered substances with pellets to minimize dust exposure.
The SIN List ("Substitute It Now!") identifies "Substances of Very High Concern" for safer chemical choices based on EU regulations.

Laboratory Practices

Proper disposal of excess chemicals, clean equipment, and maintaining work surfaces are essential.
Ensure returned glassware is clean, undamaged, and properly stored.
Handle waste chemicals according to established disposal guidelines.

Organizational Measures

Employers must assess chemical hazards and take steps to protect worker health and safety.
Create emergency plans and organize regular health checks and monitoring systems for chemical exposure.
Keep records of accidents and illnesses to inform priority measures in hazard control.

Personal Protective Equipment

Selecting the right gloves is crucial based on workplace hazards. Different types offer varying levels of protection.
- Leather, canvas, or metal mesh gloves protect against sparks, heat, and abrasions.
- Fabric gloves safeguard against dirt and mild abrasions but not sharp objects.
- Coated fabric gloves provide slip resistance and improved protection.
Gloves must be chosen according to specific hazards to ensure adequate safety.

Fire Safety Equipment

Fire blankets are crucial for extinguishing fires on individuals by cutting off air supply.
Flammable liquids must be stored in safety cabinets designed to prevent ignition in a fire.
Safety cans are approved containers for flammable liquids, emphasizing vapor control and safe handling.
Laboratory refrigeration equipment must be explosion-proof to safely store hazardous materials.

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Description

This quiz explores the environmental and health impacts of mercury and chromium, focusing on their various forms and toxicity levels. It covers sources of pollution and the processes leading to bioaccumulation and contamination in ecosystems. Test your knowledge on these critical environmental pollutants.