Six years after the NRC review of EPA's Draft IRIS Toxicological Review of Formaldehyde: Regulatory implications of new science in evaluating formaldehyde leukemogenicity

Shortly after the International Agency for Research on Cancer (IARC) determined that formaldehyde causes leukemia, the United States Environmental Protection Agency (EPA) released its Draft IRIS Toxicological Review of Formaldehyde (\u201cDraft IRIS Assessment\u201d), also concluding that formaldehyde causes leukemia. Peer review of the Draft IRIS Assessment by a National Academy of Science committee noted that \u201ccausal determinations are not supported by the narrative provided in the draft\u201d (NRC 2011). They offered recommendations for improving the Draft IRIS assessment and identified several important research gaps. Over the six years since the NRC peer review, significant new science has been published. We identify and summarize key recommendations made by NRC and map them to this new science, including extended analysis of epidemiological studies, updates of earlier occupational cohort studies, toxicological experiments using a sensitive mouse strain, mechanistic studies examining the role of exogenous versus endogenous formaldehyde in bone marrow, and several critical reviews. With few exceptions, new findings are consistently negative, and integration of all available evidence challenges the earlier conclusions that formaldehyde causes leukemia. Given formaldehyde's commercial importance, environmental ubiquity and endogenous production, accurate hazard classification and risk evaluation of whether exposure to formaldehyde from occupational, residential and consumer products causes leukemia are critical. \ua9 2017 The Author

Dinâmica do chumbo no lago do parque Ingá, Maringá, PR, Brasil

Este trabalho analisa a dinâmica do chumbo no lago do parque do Ingá, Maringá - PR. Mensalmente durante um ano foram coletadas amostras de água e sedimentos e o pH e temperatura medidos no ato da coleta. Nas amostras de água foi determinada a Demanda Química de Oxigênio (DQO) e a concentração total de Pb na água e sedimentos. A determinação da concentração Pb na água e sedimentos foi feita com a técnica da espectrometria da absorção atômica, modalidade chama. Os valores médios mensais encontrados, em intervalos e médias globais foram respectivamente: concentração de Pb na água, em ng.mL-1, não detectado (nd) - 55,56 e 19,23; Pb em sedimentos, em µg.g-1, 48,73 - 92,87 e 71,93; pH, 7,02 - 8,23 e 7,60; temperatura, em °C, 19,33 - 27,48 e 23,73; DQO, em mg.L-1, 13,33 - 30,11 e 23,54. Uma análise dos resultados das variáveis medidas, em nível de 5% de significância permitem concluir que a concentração de Pb na água é independente dos pontos de coleta (local), mas, dependente do período de amostragem (temporalidade) e nos sedimentos dependente dos dois parâmetros.<br>This work introduce the study of lead dynamic in the lake of Ingá Park, Maringá - PR. Monthly, during a year, samples of water and sediments were collected and pH and temperature measured. In the water samples were determined the chemical oxygen demand (COD) and the total lead concentration in water and sediment samples. The determination of lead concentration in water and sediments was performed with atomic absorption spectrometer - flame technique. The monthly mean values found, presented in intervals and global mean values, were respectively: lead concentration in water (ng.mL-1), non detected (nd) - 55.56 and 19.23; lead in sediments (µg.g-1), 48.73 - 92.87 and 71.93; pH, 7.02 - 8.23 and 7.60; temperature (ºC), 19.33 - 27.48 and 23.73; COD (mg.L-1), 13.33 - 30.11 and 23.54. A survey of the lead concentration results found permit to conclude, at 5% of significance, that the lead concentration in water was independent of the sampling point (local), but dependent of the sampling period (temporality) and in the sediment dependent of the two parameters