A fourth and penultimate round of UN-led negotiations to solve global plastic pollution wrapped up in Ottawa early on Tuesday with a world-first pact said to be within reach by year's end but without a cap on the production of polymers. For the first time in the negotiations, delegates from 175 countries and observers discussed a draft of what is to become a global treaty on ending the scourge of plastics that are found everywhere from mountain tops to ocean depths, as well as within human blood and breast milk, AFP said.