Left photo is a can of paint with a paintbrush, next to the element lead. The text next to the image reads as follows: Too much lead in the bloodstream can lead to organ damage and learning difficulties, especially in young children. For this reason, the use of lead-based paint was banned in 1978. Children may still be at risk if they live in an older house with layers of peeling paint. Right photo is liquid mercury, next to the element mercury. The text next to the image reads as follows: Mercury is used in numerous industrial processes, but it is toxic and can damage the brain and nervous system. For this reason it should be handled with great care. It is particularly important to avoid inhaling mercury vapor. Bottom photo is a propeller plane spraying pesticides, next to the element arsenic. The text next to the image reads as follows: Arsenic has been known as a poison for centuries, yet compounds of arsenic were used to treat some diseases before the discovery of penicillin. Arsenic compounds are no longer used to protect crops from insect pests or to preserve wood. Drinking water can absorb arsenic as it flows over rocks. But the amount of arsenic in drinking water is limited by law to less than 50 micrograms in each liter of water. The second part of the image is titled ‘Too much of a good thing’ and the text that accompanies the caption reads: Many of the elements found in your body are needed in your body are needed in only very small amounts. Too much can often be harmful. The Food and Drug Administration provides guidelines on the safe daily quantities to take through food and supplements. The image of beef is shown with the element Zinc and the text: This trace element can be found in almost every cell of your body. Among other things, it helps to support a healthy immune system. Beef is a good source of zinc, but no more than 40 milligrams of zinc should be taken daily. Too much zinc can cause anemia by reducing iron uptake. The image of table salt is shown with the element sodium and has the following text: It is hard to avoid sodium in our diet because table salt contains a sodium compound (sodium chloride). Everybody needs some sodium each day to maintain water balance and nerve function. But too much sodium i.e. more than 3 grams daily can cause high blood pressure. The image of Brazil nuts is shown with the element selenium and has the following text: This trace element helps maintain a healthy immune system. Brazil nuts are a good source of selenium, as are fruits and vegetables. While selenium supplements may be useful for some people, no more than 400 micrograms should be taken daily. Too much selenium can cause nerve damage.