Impact of ISO 14001 Environmental Management System on Key Environmental Performance Indicators of Selected Gold Mining Companies in Ghana

Table 1

Ambient air quality (PM10).

Year	Mean; (μg/m³)	Maximum; (μg/m³)	Minimum; (μg/m³)	EPA guideline value; (μg/m³)
2003	53.94	109.92	18.69	70
2004	54.36	158.8	4	70
2005	71.98	202.3	18.3	70
2006	79	133	25	70
2007	78.6	138.6	22.7	70
2008	37.13	109.91	1.33	70
2009	44.33	68	20	70