9" blade found today

Today this knife was added to my tally of dangerous items found when litter picking locally.  I picked up my 73rd face mask today too (why do people do this - I only started counting last November).  Recently I have found a claw hammer, bolt cutters, another knife and a gemmy.  My local park has lots of undergrowth and winter die down has exposed rubbish jettisoned when it was more easily hidden.