can I directly use variables from URI?

[eluser]basementDUDE[/eluser]
Is it safe to use the variables from URI directly? I have used the active record class in my model, so I don't need to worry database injection attack right? any security issue with my code? any advise will be really appreciated.

Code:

function showItem($id)
{
//load model... then call model function

$this->item_model->get_item($id);

//load views...
}

in the item_model class

Code:

function get_item($id){

$this->db->where('items.id', $id);

$result = $this->db->get('items');


return $result->result_array();
}