Avaliação da qualidade do ar: concentrações de material particulado mp10 e mp2.5 no interior de uma instituição de ensino de fortaleza (ce, Brasil)

http://dx.doi.org/10.5902/2179460X13744 The indoor air pollution can pose risks to the human health much larger than the air outside because about 90 % of people’s time is spent indoors. This paper aims to study the concentrations of particulate matter (PM10 and MP2.5) within the Federal Institute for Education, Science and Technology of Ceará (Brazil), in Fortaleza campus, aiming to meet the levels at which students and employees are exposed daily to these pollutants. We used the particle counter Aerosol Mass MeOne 831 ® to obtain the data of concentration of particulate matter PM10 and MP2.5 in five environments IFCE : 2 reception rooms ( P1 and P2 ) ; 2 classrooms ( P3 and P5 ) and 1 lab ( P4 ) . Were analyzed daily and continuously (every minute) concentrations of particulate material. The daily concentrations of ambient attended the Brazilian ANVISA standard for PM10 of 80 µg/m³, and international WHO PM25, of 25µg/m³. In analysis in continuous some high concentrations were found, especially in the reception rooms (P1 and P2). Were observed very high concentrations in P4 (Lab) during cleaning (> 600 µg/m³).A poluição do ar interior pode apresentar riscos à saúde humana muito maiores que o ar exterior, pois cerca de 90% do tempo das pessoas é passado em ambientes interiores. Este trabalho se propõe a estudar as concentrações de partículas em suspensão (MP10 e MP2.5) no interior do Instituto Federal de Educação, Ciência e Tecnologia do Ceará, campus na cidade de Fortaleza, com o objetivo de conhecer os níveis em que alunos e funcionários estão expostos diariamente a esses poluentes.  Utilizou-se o contador de partículas Aerosol Mass 831 MetOne® para obtenção dos dados de concentração de material particulado MP10 e MP2.5 em cinco ambientes do IFCE: 2 salas de recepção (P1 e P2); 2 salas de aula (P3 e P5) e 1 laboratório (P4). Analisaram-se as concentrações diárias e contínuas (a cada minuto) de material particulado. As concentrações diárias dos ambientes atenderam o padrão brasileiro da ANVISA para MP10, de 80 µg/m³, e internacional da OMS para MP2.5, de 25 µg/m³ .  Na análise em contínuo foram encontradas algumas concentrações elevadas, principalmente nos ambientes de recepção (P1 e P2). Observaram-se concentrações bastante elevadas no P4 (laboratório) durante a limpeza (> 600 µg/m³)

High-concentration carbamide peroxide can reduce the sensitivity caused by in-office tooth bleaching: a single-blinded randomized controlled trial

Objectives: A single-blinded, randomized, parallel clinical trial evaluated the use of 37% carbamide peroxide (CP) on bleaching effectiveness and tooth sensitivity reported by patients undergoing in-office tooth bleaching, in comparison with the results of using 35% hydrogen peroxide. Material and Methods:Forty patients were allocated to receive two sessions of in-office tooth bleaching using either 35% hydrogen peroxide (HP) or 37% CP. Each patient’s sensitivity level was evaluated during and up to 24 h after bleaching. The effectiveness of the bleaching procedures was evaluated with a spectrophotometer one week after each session and 30 days after the last session. The impact of tooth bleaching on the patients’ perceptions regarding smile changes, in addition to the bleaching procedures and their results, were also recorded. Absolute and relative sensitivity risks were calculated. Data on sensitivity level were analyzed using the Mann-Whitney or T-test, and data from the color evaluation were subjected to 2-way repeated measures ANOVA. Results: The use of CP reduced the risk and level of tooth sensitivity to values close to zero, whereas the difference between the bleaching agents disappeared after 24 h. An increased bleaching effect was observed for HP, mainly due to an improved reduction of redness and yellowness. Participants perceived improved tooth bleaching for HP and reduced sensitivity for CP, but no differences regarding the comfort of the techniques were noted. Conclusions: In our study, 37% CP resulted in reduced tooth sensitivity but decreased the tooth bleaching effectiveness. However, both bleaching agents resulted in high levels of patient satisfaction