**4.4 Neurological effects**

Exposure to heavy metals (e.g., lead, mercury) and dioxins have been corelated with several neurological effects in humans. Lead exposure occurs through inhalation, ingestion and dermal absorption. Conditions such as neurological damage (mimics Ca and disrupts Ca homeostasis), lower IQ and attention impairment of hand-eye co-ordination and encephalopathy has been associated with chronic exposure of lead [40]. It is well recognised teratogen can easily pass through placenta and can cross blood–brain barrier. Therefore, it can cause more harm to the foetus. Mercury (methyl mercury) is another heavy metal that effects the nervous system. Organic mercury is fat soluble and can be distributed in the central nervous system where it is oxidised to Hg2+ and causes neurological damage. Symptoms include

**Figure 5.** *Mechanism of toxicity of PM bound heavy metals.*

memory loss, narrowing of vision, loss of muscle coordination and emotional instability [46].
