Steel industry is one of the biggest contributors of greenhouse gas emissions in Indonesia, with a significant contribution to the total national emission of up to 1.36 billion tons of CO₂e in 2023, where industrial sectors contributed 59.85 million tons of CO₂e. The most used technology, Blast Furnace–Basic Oxygen Furnace (BF–BOF), produces an average emission intensity of 2.2 tons of CO2eq per ton of steel, way higher than the alternative technology Electric Arc Furnace (EAF), which only produces about 0,5 tons of CO2eq per ton of steel. Nevertheless, 75% of the national steel industry is still using BF–BOF, and the industrial development plan until 2060 shows that this high-emission technology will still dominate the industry, with up to 75% of production capacity. PT Krakatau Posco, as the largest BF–BOF-based integrated steel plant in Indonesia, produces up to 3 million tons of slab steel per year and operates large facilities such as Sinter Plant with the capacity of 9.38 million tons of sinter/year, Blast Furnace with the capacity of 8.26 million tons of hot metal year, and Coke Oven Plant that produces 2.64 million tons of coke/year. With phase II expansion, the capacity for slab steel reaches 6.0 million tons, HRC reaches 4.5 million tons and CRC achieves 1.8 million tons per year, strengthening its position as one of the largest emission contributors in the manufacturing sector.

At the heart of the steel industry expansion, Tegal Ratu Village, Cilegon Municipality, located in the nearest radius of the industrial park, is facing a high-level of air pollution risk. With a total population of 11,987 people, this region has become the area with highest ARI cases in Cilegon Municipality. Data from Public Health Center (Puskesmas) of Ciwandan reveals that ARI was the most prevalent disease in 2016-2024. A survey by AEER involving 94 respondents who had lived there for more than 10 years indicates that many experienced chronic coughing, shortness of breath, and other respiratory complaints related to pollutant exposure. The steel industrial processes produced PM2.5, which recorded in the EIA measurement to have exceeded the quality standard of South Korea in several monitoring spots. In other countries, similar impacts were also recorded, for instance in Pennsylvania, where 70% of children were exposed to higher amount of PM2.5 and 22.5% of them were diagnosed with asthma. The global findings show that PM exposure causes the increase of inpatient cases of pneumonia and bronchitis. For silicosis cases, data in Poland indicates that 2,066 workers were suffering from this disease in 2000–2019, showing how high the risk of industrial exposure to lung health is.