In this paper the sulfur dioxide levels recorded in the environmental station called “Sindicato de Obreros” of the Metallurgical Complex of La Oroya (CMLO, by its spanish acronyms ) was analyzed between January 1998 to January 2009. This station has the longest historical record and shows an intermediate level of sulfur dioxide concentrations in front of the others stations of CMLO Environmental Monitoring Network, although, its concentrations frequently exceeded the maximum amount allowed by Peruvian environmental standards. Even assuming that due to the resumption of its operations, the Metallurgical Complex of La Oroya will produce (and will emit) as like its historical lows (1998-2009) it´s estimates that during the period January to March 2010 sulfur dioxide levels in the atmosphere would still be higher than the permitted levels.

Although almost all human activities produce noise, these may keep in a such level that can’t produce an adverse impact on the people health’s and be according to its environment, so, the countries rule the noise production and adopt environmental standards for noise. In this paper, the document titled : “Modificación al Plan de Monitoreo Ambiental Suplementario de Yanacocha Oeste” is considered and analyzed technically like an example of the environmental transcendence for these kind of documents when are presented to the sector authority.

En el presente trabajo, se analizan los niveles de dióxido de azufre registrados durante el periodo enero 1998 a enero 2009, en la estación de monitoreo ambiental “Sindicato de Obreros” del Complejo Metalúrgico de La Oroya (CMLO). Esta estación cuenta con el registro histórico más extenso y presenta niveles de concentración de dióxido de azufre intermedios frente a las demás estaciones de la Red de Monitoreo del CMLO, aunque, las concentraciones que registra frecuentemente superan los valores máximos permitidos por las normas ambientales peruanas. Aún suponiendo que debido al reinicio de sus operaciones, el Complejo Metalúrgico de La Oroya produzca (y emita ) a sus niveles mínimos históricos (1998-2009), se estima que durante el periodo Enero-Marzo 2010, los niveles de dióxido de azufre en la atmósfera serían todavía superiores a los niveles permitidos.

Although almost all human activities produce noise, these may keep in a such level that can’t produce an adverse impact on the people health’s and be according to its environment, so, the countries rule the noise production and adopt environmental standards for noise. In this paper, the document titled : “Modificación al Plan de Monitoreo Ambiental Suplementario de Yanacocha Oeste” is considered and analyzed technically like an example of the environmental transcendence for these kind of documents when are presented to the sector authority.