New research has found that nearly one in three children across the world have high levels of lead in their bloodstream. The study carried out by UNICEF and environmental group Pure Earth blamed increasing levels of lead pollution and says that the levels are high enough to impair the development of brains, nervous systems and vital organs such as heart and lungs. 800 million children had lead levels of 5 micrograms per deciliter or higher in their bloodstream. The WHO and US CDC called the findings 'cause for action.' The report cites inadequate battery recycling and open-air smelters among the lead polluters. Lead-acid batteries could be a key culprit, with nearly 85% of the lead used worldwide going into their production, the report added.