The Environmental Protection Ministry banned schools from organizing visits to the Pelenica park east of Skopje, because of fears that the soil could be contaminated with a dangerous, cancer inducing poisonous substance.

Pelenica is close to the now largely defunct OHIS chemical plant. Large reservoirs there store lindane, which is used in treating lice, but is dangerous to humans and is believed to cause cancer.

There are a total of 8.000 tons of lindane stored in OHIS. Only recently a plan was put in place to remove it, and the contaminated soil underneath the reservoirs.