QUANTITATIVE ASSESSMENT OF NOISE POLLUTION IN THE VICINITY OF PORT HARCOURT REFINING COMPANY, NIGERIA: A GEOSPATIAL ANALYSIS APPROACH

The Port Harcourt Refining Company (PHRC) is a central component of Nigeria’s oiland-gas sector, refining crude oil into vital products and thereby contributing
significantly to national energy security and economic development. Yet, its
operations also entail substantial environmental burdens, among them noise
pollution, which can impose serious health and well-being risks on workers and
surrounding communities. This study aims to quantitatively assess noise-pollution
levels around the PHRC oil-refinery complex in Rivers State, Nigeria, employing
geospatial (GIS) methods to map sound-pressure distributions in the immediate area.
Using a calibrated sound-level meter, we measured noise levels (dB (A)) at radial
distances of 0 m (at the source), 5 m, 10 m, 15 m, 20 m, 25 m, 30 m, 35 m, 40 m, 45 m
and 50 m from both PHRC New and Old plant units, at a consistent measurement
height of 1.5 m above ground in accordance with ISO 8297: 1994. Geographical
coordinates of each measurement point were collected, and contour maps of soundpressure levels were generated using GIS software to identify spatial noise “hotspots”. Key findings reveal peak noise levels of approximately 105.8 dB (A) at the Old
Plant’s source point and 102.0 dB (A) at the New Plant, followed by a steady decline in
intensity with distance. At 30 m radial distance, readings dropped to approximately
66-69 dB (A), and at 50 m to ~40 dB (A). Many points within 0–20 m of the plants
exceeded Nigeria’s industrial noise limit of ~85 dB (A) (National Environmental
Standards & Regulations Enforcement Agency regulation) and therefore constitute
high-exposure zones. GIS‐based contour maps enabled clear visualisation of the
spatial spread of noise, with the highest exposure zones clustered around the plant
perimeters. These elevated noise levels carry important implications: for refinery
workers, the risk of hearing damage, stress, and sleep disturbances is elevated; for
nearby residential communities, the ambient noise may disrupt daily life, raise
cardiovascular risk and reduce quality of life. From a policy perspective, the findings
underscore the need for continuous monitoring of industrial noise, use of GIS mapping
for targeted mitigation, and the development of comprehensive noise-management
strategies in refinery contexts.