what is a loose spice? I read this sentence 'We probably buy a variety of ground spices every month and when packaged spices of our choice are not available, we end up buying loose spices. This increases our risk of consuming adulterated spices.'

Ground spices means the spice has been ground down into a coarse or fine powder.  However what's a 'packaged spice' and a 'loose spice'?  I know ground spices are packaged small bottles or plastic bags or what am I not understanding?
I take the term "loose" to mean spices sold from large containers, scooped into a bag, rather than a sealed and packaged off-the-shelf product.



A sealed container, produced commercially, is (presumably) inspected and regulated to avoid adulteration. When you buy from an open container at a market or store, you have no way to know if it was mixed with something. 

And still, I prefer to buy fresh loose spices, from vendors I trust.