Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Reference Noise Exposure Air Pollution Exposure Health Outcome Sample Adjustments Direction of Evidence
Hypertension and
Atherosclerosis
Sørensen et al,
2011 [8]
RTN SOUNDPLAN
using Nordic
prediction model
from 5 years prior to
enrolment to
2000–2002.
Category: