As nicotine pouches surge in popularity, the World Health Organization is pressing governments to tighten controls, warning that the highly addictive products are being "aggressively marketed" in ways that hold particular appeal for younger people. The small pouches, placed under the lip to deliver a nicotine buzz, have quickly emerged as a crucial growth area for major tobacco companies as cigarette smoking continues its long decline. That rise, however, has drawn mounting criticism from campaigners and researchers over the…