Lead, ingested or inhaled, is a health hazard. After the addition of lead to petrol has been banned, what still are lead poisoning sources?

I. Smelting units

II. Pens and pencils

III. Paints

IV. Hair oils and cosmetics

Select the correct answer using the codes given below:

Consider the following statements:

Chlorofluorocarbons, known as ozone-depleting substances, are used:

I. In the production of plastic foams

II. In the production of tubeless tyres

III. In cleaning certain electronic components

IV. As pressurizing agents in aerosol cans

Which of the statements given above is/are correct?