Air pollution in Dhaka has reached alarming levels specially in terms of lead concentration. According to a survey conducted by the Bangladesh Atomic Energy Commission (BAEC), the air in Dhaka contains the highest density of lead in the world. The report states that every year 50 tonnes of lead are emitted in Dhaka's air. The emission levels are particularly high in the dry season, especially from November to January. Yet another survey has revealed that lead concentration in the blood of Dhaka's residents are exceptionally high. Compared to the tolerable limit of eight parts per million (PPM), the blood of automobile drivers and office-goers are found to carry lead with a concentration as highas 120 PPM.