"expressed concern regarding" is correct and usable in written English.
You can use it to describe the act of expressing a concern or worry about a particular topic or issue. For example, "The President expressed concern regarding the increasing unemployment rate."
GOI participants expressed concern regarding Chinese and Russian cooperation with respect to enhanced Iranian sanctions.
Collaborative and peer-to-peer learning were common benefits from SNSs while some expressed concern regarding cyber-bullying and privacy.
A number of governments have expressed concern regarding the disappearances, which some diplomats fear were abductions by Chinese agents in Hong Kong and Thailand.
Eva's neighbors, as well as members of the international scholarly community, have expressed concern regarding the effects of these cats on their surroundings.
They were put to death just days after the visit to Iran by Louise Arbour, the UN High Commissioner for Human Rights, in what appeared to be a calculated defiance of the UN's expressed concern regarding the oppression of Ahwazi Arabs.
Two oncologists expressed concern regarding the patients' rating of symptoms.
The Commissioned expressed concerns regarding "the lack of respect for the independence of the judiciary and the instability faced by judicial institutions".
The government said that those responding to the consultation held differing views on this and some expressed concerns regarding extending the duty to adults, including the risk that this could deter women from seeking medical advice and assistance.
Participants described feelings of anxiety and depression when UTIs were present and expressed concerns regarding discrimination if symptoms became obvious to others, specifically in the context of daily living and social participation.
In 2008, the US National Toxicology Program's Center for the Evaluation of Risks to Human Reproduction (NTP-CERHR) expressed concerns regarding BPA's potential health effects, and suggested improved study designs and methodologies that they believed would address those concerns.
From time to time, AT&T has expressed concerns regarding network efficiency and potential network congestion associated with certain applications, and Apple takes such concerns into consideration.
