Public health officials are closely monitoring the mu variant of the coronavirus now circulating in Los Angeles County, though they say the delta variant remains the greatest cause for concern. Labeled as a “variant of interest” on Aug. 30 by the World Health Organization, the mu variant has been identified in 167 cases to date in L.A. County, the county Department of Public Health said in a news release Friday. “The identification of variants like Mu, and the spreading of variants across the globe, highlights the need for L.A. County residents to continue to take measures to protect themselves and others,” Barbara Ferrer, the county’s public health director, said in a statement. The mu variant was first identified in Colombia in January 2021. It has since popped up in 39 other countries, the L.A. County officials said. Although further studies are needed to determine if the mu variant is more contagious than other COVID-19 strains, it has been found to have key mutations linked