The pig iron industries are supplied by the mining company Vale, which has one of the company's most important railway loading yards in the city, which, in addition to supplying iron ore to the industries in Açailândia, delivers fuel and collects grains [7]. 

Piquiá de Baixo is one of the oldest neighborhoods of Açailândia. The region of açailândia was occupied by migrants from the 1960s and the municipality was founded in the 1981. The pig iron industries arrived in the second half of the 1980s, with the beginning of the mineral exploration in Carajás by Vale (former CVRD). 

The extraction of native wood for the production of charcoal to be used in the pig iron industries was responsible for large deforestation of native forest and, later, also for stimulating the eucalyptus plantations in the region. The productive process of coal uses precarious production systems, which are highly negative for workers and the environment. It also generates large amounts of pollutants, mainly carbon monoxide, which has serious effects on health, such as respiratory diseases [6, 8]. 

Since 2007, the Associação de Moradores de Piquiá de Baixo (the Association of Residents of Piquiá de Baixo) has forwarded complaints to different agencies about the gravity of the situation due to the high levels of pollution. During this period, the Association gained the support of the Centro de Defesa da Vida e dos Direitos Humanos de Açailândia (CDVDH) and of the Missionários Combonianos – a congregation of the Catholic Church that articulated a network of resistance of those affected by Vale’s Carajás Railroad originating the Rede Justiça nos Trilhos in 2007. In the same period, environmental and public health technical reports were conducted attesting that rates of skin disease, respiratory and vision ailments in the population are much higher than the national average. 

In 2008, the Association held a consultation with all Piquiá residents and they decided unanimously chose to fight for their collective resettlement in a new location, free from contamination. The community emphasizes that they would never have wanted to leave their lands, but they decided to do so because of the socioenvironmental impacts of pig iron production, especially the ones related with health conditions that affect seriously children, pregnant women and the elderly [4]. The case attracted the attention of human rights organizations nationally and internationally. 

In 2011, the Justiça nos Trilhos, with the support of Fédération internationale des droits de l'homme (FIDH) and Justiça Global, published a report analyzing Vale's role in the conflict, the history of affected communities and the main violations of human rights and health problems in Açailândia. According to the report, 65.2% of people had respiratory problems in Piquiá de Baixo [5]. In March 2011, the State Public Prosecutor, defending the urgency of the resettlement of the community of Piquiá de Baixo, instituted a Public Civil Inquiry with the objective of analyzing the injuries to the citizenship right in Piquiá and identifying those responsible for them. The Inquiry was the basis for the Conduct Adjustment Agreement (TAC), firmed in May 2011, which determined actions and procedures for the "Resettlement Program for the Families of the Piquiá de Baixo Community." 

These measures would be carried out through the expropriation of a 38-hectare site called Sítio São João by the Açailândia prefecture, and the compensation of this expropriation to be paid by the organization of pig iron companies of Maranhão – Sindicato das Indústrias de Ferro Gusa do Estado do Maranhão (Sifema) [7]. In the following year, the community faced many obstacles and delays to enable the continuation of the resettlement process. Sifema delayed the transfer of funding needed to build the new neighborhood and Vale didn’t recognize its responsibility in the conflict [1, 2]. 

In 2014, the community of Piquiá, with support from the MST, blocked access to Açailândia pig iron industries to pressure Sifema to make the agreed payments [3]. In 2014, the new community project was presented and approved by Caixa Econômica Federal and in 2015 was selected by the Ministry of Cities, which guaranteed about 60% of the (public) resources needed to build the new neighborhood. Of the U$ 7 million needed for the infrastructure of the new neighborhood, only U$ 500,000 (7.5%) were contributed by pig iron companies (Sifema), and another U$ 1.5 million were agreed, after much pressure, with Vale SA and Vale Foundation [9]. 

In 2018, the Associação de Moradores de Piquiá de Baixo wrote: “For more than 10 years, the community of Piquiá de Baixo has been waging a struggle to be resettled in a place far from pollution. The process could have been more agile if it were not for the companies' resistance to recognize their responsibility and to effectively participate in the composition of resources for resettlement” [9]. Finally, after ten years of struggle, by the end of 2018, the works for the construction of the resettlement of Piquiá de Baixo are about to begin. And the name of the new neighborhood could not be more symbolic: Piquiá da Conquista (Piquiá of the Conquest) [10].

- Fergumar: 216,000 tons of pig iron per year.

- Vienna Siderúrgica S/A: 480,000 of pig iron per year.

- Siderúrgica do Maranhao S/A and Companhia Siderúrgica Vale do Pindaré: 564,000 of pig iron per year [6].