The phrase "are of considerable concern" is correct and usable in written English.
It can be used when discussing issues or topics that are significant or troubling in nature.
Example: "The rising levels of pollution in urban areas are of considerable concern to environmentalists."
Alternatives: "are a significant worry" or "are a major issue".
The toxicity of chemicals required for coupling and their slow release during the separation process are of considerable concern.
At that level, "future changes in climate are of considerable concern," notes climatologist Tom Wigley of the National Center for Atmospheric Research in Boulder, Colorado.
The relatively large number of drug holidays reported in this study, with a dosing interruption of 3 or more days, are of considerable concern.
These differential impacts are of considerable concern, since they may cause alterations to microbial community dynamics that may, in turn, impact negatively upon the health and productivity of crops.
These striking observations, if validated, are of considerable concern, particularly as long-term treatment with lithium has been associated with risk of pathological and pathophysiological changes in renal function that call for regular, routine clinical monitoring of indices of renal function among patients treated long-term with lithium (Bauer et al. 2006; Baldessarini 2013).
In particular, criminal cases against journalists are of "considerable concern".
He added that Guardian Australia's revelations about the nature and definition of Abdellatif's convictions were of "considerable concern" to the AFP.
As Professor ST Carrington, head of astronomy and astrophysics, has written to Cheshire East Council: "The potential electrical interference generated from this development is of considerable concern".
"It has to be of considerable concern," said Steve Roberts, a longtime Iowa Republican who served as one of the state's national committeemen for a decade.
Paul Farrelly, another Labour MP, said: "It would be of considerable concern if the sort of bias we see in the Murdoch press was fed through to our children through the school system".
Saints' Heineken Cup opener against Glasgow is less than a month away, while news of Foden's injury will be of considerable concern to the England head coach, Stuart Lancaster.
