Environmental Issues

Lead is a toxic heavy metal that enters the body from leaded petrol exhaust, lead paints, batteries and contaminated water.
It damages the nervous system (especially in children), kidneys and blood formation, since it inhibits enzymes of haem synthesis.
Normal blood lead levels are only a few micrograms per 100 ml.
A blood lead level of 10 $\mu g$/100 ml (10 $\mu g$/dL) has been taken as the level of concern; at or above this value harmful effects, especially on the mental development of children, begin, so it is considered alarming.
So lead concentration in blood is considered alarming if it is 10 $\mu g$/100 ml.

Terra rossa (Italian for 'red earth') is a red clayey soil formed on limestone in Mediterranean regions. Its name refers to its red colour (due to iron oxides), not to roses, and it has no special suitability for growing roses. So this pair is not correctly matched.
Chernozems (black earth) of the grasslands of Russia and Ukraine are very rich in humus and are considered among the most fertile soils in the world; correctly matched.
Black soil (regur) of the Deccan is clayey and rich in calcium carbonate, magnesium and iron; correctly matched.
Laterite soil, formed by intense leaching in hot, wet regions, is rich in hydrated oxides of aluminium and iron; correctly matched.
So the pair not correctly matched is Terra rossa – most suitable for roses.