Mayumi Silva Kawamotoa, Tatiane Tagino Comina, Wiclef Dymurgo Marra Juniorb and
Mônica Lopes Aguiara,*.
Laboratory of Environmental Control, Department of Chemical Engineering, Federal University of São
Carlos, Rod. Washington Luís - km 235, CEP: 13565-905, São Carlos - SP, Brazil.
Departmentof Hydraulics and Sanitation, EESC – USP
The concern about the indoor air quality and the production, emission and utilization of many
chemical substances and their environmental and health effects has increased during the last years.
The World Health Organization (WHO) estimates that 50% of the world population suffers with poor
indoor air quality (IAQ) and human exposure to potential toxicsubstances can harm the cardiovascular
and respiratory system, and cause headaches, drowsiness and loss of concentration. Most people in
developed countries spend up to 90% of their time indoors. Taking into account that each person
inhales about 22m³ air per day, inhalation of indoor air is potentially the major determinant of human
exposure to many pollutants . High temperature andhumidity levels can also increase
concentrations of some pollutants. A potential relationship between indoor air quality and CO2
includes the healthy effects of elevated CO2 concentrations, the impact of CO2 on occupant
perceptions, the relationship between CO2 concentrations and the concentrations of other indoor
contaminants, and the relationship between CO2 and outdoor air ventilation rates. Insome situations,
indoor CO2 concentrations can be used to evaluate building ventilation, specifically air change rates
and percent outdoor air intake .
This paper presents measurements of indoor CO2 concentrations, humidity and temperature levels
during four months in a chemical industry located in the city of Sao Carlos (Sao Paulo, Brazil) that
produces paints, varnishes, solvents andleather products. The monitoring consisted in weekly partial
samplings lasting about four hours into a journey of 8 hours daily. The results were compared with the
legislation relating to occupational hygiene: Tolerance limits established in the NR-15 (Brazilian
standard for Unhealthy activities and operations) and RE/ANVISA Nº. 9. For measurements of CO 2 , it
was used a portable gas meter (modelIR-MultiRAE PMG54 mark RAE Systems), which draws in the
air and through non-dispersive infrared analyzes and displays the carbon dioxide concentrations in
ppm and for measurements of humidity and temperature it was used a digital Thermo-Hygrometer,
mark Rotronic, model Hygropalm 0. After four months of monitoring, the average CO2 concentration
was about 556 ppm in the indoor air of theproduction area of the industry, the average indoor
humidity was 45% and the average indoor temperature was 27ºC. The Figure 1 summarizes the
monthly values of CO 2 for the average concentrations, as well as the minimum and maximum
concentrations found and the Figure 2 summarizes the monthly values of humidity and temperature.
Carbon Dioxide Concentrations
CO2 Concentrations (ppm)
Figure 1. Carbon dioxide concentrations for the months of monitoring.
Humidity and Temperature Levels
TEM PERATURE OUTDOOR
HUM IDITY LEVELS OUTDOOR
TEM PERATURE INDOOR
HUM IDITY LEVELS INDOOR
Figure 2. Humidity and Temperature levels for the months of monitoring.