A spokesperson for the Health and Safety Executive said, “After previous concerns about air quality related to diesel were raised, HSE did investigate, and though we found some issues, these had already been addressed by the dutyholder and no further action was necessary. At that time, management of silica was considered, but no issues were found. We are now making some enquiries into the air quality at Bond street, but we have no evidence to suggest these deaths are linked or caused by work at Crossrail.”

A spokesperson for Costain Skanska joint venture (CSJV) said, “Our condolences go out to the friends, families and colleagues of those who have recently passed away. The safety of all colleagues working at CSJV sites is absolutely paramount. Independent air quality monitoring at Bond Street is conducted at regular intervals as well as for specific planned construction activities. This monitoring has never revealed anything concerning or unexpected. Any concerns raised about health and safety on site will always be fully investigated with the appropriate action always taken.”

A Crossrail spokesperson said, “Our thoughts are with our colleagues at Bond Street and the friends and families of those who have passed away. Crossrail Ltd demands the highest standards of health and safety across the project and we continue to work closely with our Bond Street contractor Costain Skanska Joint Venture in support of making sure this is the case. Crossrail and its contractors monitor the air quality at all sites to ensure that compliance requirements are met and that workers are not exposed to unacceptable levels of dust.”