Air monitoring conducted by the City of Paramount detected elevated levels of hexavalent chromium. In response, the South Coast Air Quality Management District (SCAQMD) has resumed additional air monitoring and is conducting focused investigations to determine potential emission sources. This includes facility inspections as well as review of source testing and permitting information to assess whether additional regulatory actions are needed.

For the latest monitoring results and investigation updates, visit SCAQMD's Paramount Emissions Investigation webpage. Additional air monitoring data collected by Trinity Consultants on behalf of the City of Paramount is available on Paramount’s Environmental air monitoring webpage.

Hexavalent chromium, or chromium-6, is a metal used in certain industrial processes, such as metal plating, leather work, and welding. Breathing chromium-6 does not generally lead to immediate health symptoms. However, breathing it at higher levels over many years can irritate the lungs and may worsen breathing problems, such as asthma, and cause irritation to the nose, throat, and lungs. Long-term exposure to high levels may also increase the risk of certain cancers, such as lung and nasal cancer. Chromium 6 is a known human carcinogen.

Air monitoring for hexavalent chromium (chromium 6) and other toxic air contaminants in Paramount began in 2013 after community complaints of metallic odors thought to be coming from nearby metal forging and grinding operations. Monitoring continued for several years. Following South Coast AQMD’s extensive 2016–2021 air toxics monitoring and investigation, the City of Paramount has continued monitoring hexavalent chromium, providing an early indication when levels change and working with South Coast AQMD to conduct additional monitoring and investigative follow-up if needed.