Twitter Inc is merging teams that concentrate on eliminating toxic material and spam bots, following complaints from a former executive that the firm failed to execute either job adequately. According to an email to employees, the social media company will combine its health experience team, which works on reducing misinformation and harmful content, with the Twitter service team, which is responsible for reviewing profiles that users report and removing spam accounts, into a new group called "Health Products and Services (HPS)." Ella Irwin, vice president of product for health and Twitter service, who joined the business in June, will lead the new group.