As the curve shows the quantity of the chemical's concentration in the air which people usually can get into your body, which can cause adverse effects, even if they have been in less quantities.
A curve that shows the concentration of chemicals in the air, regular people can get into the body, which may cause adverse effects, although it has been in small quantities.
A curve that shows the concentration of chemicals in the air, which ordinary people can get into the body, which may cause adverse effects, although will be a small amount.