A Probabilistic Arsenic Exposure Assessment for Children Who Contact CCA-Treated Playsets and Decks, Part 1: Model Methodology, Variability Results, and Model Evaluation

Concerns have been raised regarding the safety of young children who may contact arsenic residues while playing on and around chromated copper arsenate (CCA)-treated wood playsets and decks. Although CCA registrants voluntarily canceled the production of treated wood for residential use in 2003, the potential for exposure from existing structures and surrounding soil still poses concerns. The EPA's Office of Research and Development developed and applied the probabilistic Stochastic Human Exposure and Dose Simulation model for wood preservatives (SHEDS-Wood) to estimate children's absorbed dose of arsenic from CCA. Skin contact with, and nondietary ingestion of, arsenic in soil and wood residues were considered for the population of children in the United States who frequently contact CCA-treated wood playsets and decks. Model analyses were conducted to assess the range in population estimates and the impact of potential mitigation strategies such as the use of sealants and hand washing after play events. The results show predicted central values for lifetime annual average daily dose values for arsenic ranging from 10(-6) to 10(-5) mg/kg/day, with predicted 95th percentiles on the order of 10(-5) mg/kg/day. There were several orders of magnitude between lower and upper percentiles. Residue ingestion via hand-to-mouth contact was determined to be the most significant exposure route for most scenarios. Results of several alternative scenarios were similar to baseline results, except for the scenario with greatly reduced residue concentrations through hypothetical wood sealant applications; in this scenario, exposures were lower, and the soil ingestion route dominated. SHEDS-Wood estimates are typically consistent with, or within the range of, other CCA exposure models.     

Patterns of Belief In Social Movements: Clarifications from an Analysis of Environmental Groups*

Several explanations of social movements rest on the assumption that participants are bonded together by a commonly-held set of beliefs differentiating them from non-participants. This is especially true of Smelser's theory of collective behavior and its central concept, the generalized belief. Components of the generalized belief are examined in light of recent studies of groups within the environmental movement; results disclose significant heterogeneity, especially regarding responsibility for environmental problems and visions of solutions. Data from a total census of a focal group within one urban environmental coalition are presented and the distribution of beliefs across its structure described. The degree of homogeneity of beliefs decreases with movement from the center to the periphery of the group. These analyses suggest that collective action by social movement organizations results from emergent internal processes and structures rather than initial consensus among movement participants.     

Weberian Political Sociology and Sociological Disaster Studies

The specialized field of disaster studies seems to be moving farther away from mainstream sociology, to the detriment of both. For sociologists working in this field, application of Max Weber's political sociology is proposed as one way to reconnect their research with longstanding concerns of the discipline. Weber's political sociology contains a conflict model focusing on structured inequalities of class, status, and power. Its relevance to both contemporary sociology and sociological disaster studies is illustrated through a reexamination of one of the early classic studies of disaster. The paper concludes with an overview of Weber's thoughts about the role of values in research and a brief comparison of Weber's political sociology with alternative theories.     

Abuse during and before pregnancy: prevalence and cultural correlates

This study examined the prevalence of abuse during pregnancy and the influence of cultural norms and acculturation on abuse in 1,004 Mexican American, Puerto Rican, Cuban American, Central American, African American and Anglo American women. Women were recruited from consecutive delivery logs in general community hospitals in Florida and Massachusetts. The Index of Spouse Abuse and the Abuse Assessment Screen ascertained history of adult physical, sexual, and emotional abuse, abuse during pregnancy, and childhood sexual abuse. An Interview Protocol assessed cultural attitudes, acculturation, and demographic information. Hispanic American women, as a whole, did not differ significantly from Anglo American women in their prevalence of abuse during pregnancy, after controlling for sociodemographic variables. However, Cuban American and Central American partners were significantly less likely to abuse their pregnant partners than were other groups even after adjustment. Women who spoke only Spanish (less acculturated) were less likely to report physical abuse from their partners both before and during pregnancy. Cultural norms, such as a partner's belief in wife/mother role supremacy and cultural group acceptability of men hitting women, were significantly positively related to both physical and emotional abuse. Other risk factors for abuse were the abuser not being the biological father of the baby, low income and little education, and being unmarried.     

A Probabilistic Arsenic Exposure Assessment for Children Who Contact Chromated Copper Arsenate (CCA)-Treated Playsets and Decks, Part 2: Sensitivity and Uncertainty Analyses

A probabilistic model (SHEDS-Wood) was developed to examine children's exposure and dose to chromated copper arsenate (CCA)-treated wood, as described in Part 1 of this two-part article. This Part 2 article discusses sensitivity and uncertainty analyses conducted to assess the key model inputs and areas of needed research for children's exposure to CCA-treated playsets and decks. The following types of analyses were conducted: (1) sensitivity analyses using a percentile scaling approach and multiple stepwise regression; and (2) uncertainty analyses using the bootstrap and two-stage Monte Carlo techniques. The five most important variables, based on both sensitivity and uncertainty analyses, were: wood surface residue-to-skin transfer efficiency; wood surface residue levels; fraction of hand surface area mouthed per mouthing event; average fraction of nonresidential outdoor time a child plays on/around CCA-treated public playsets; and frequency of hand washing. In general, there was a factor of 8 for the 5th and 95th percentiles and a factor of 4 for the 50th percentile in the uncertainty of predicted population dose estimates due to parameter uncertainty. Data were available for most of the key model inputs identified with sensitivity and uncertainty analyses; however, there were few or no data for some key inputs. To evaluate and improve the accuracy of model results, future measurement studies should obtain longitudinal time-activity diary information on children, spatial and temporal measurements of residue and soil concentrations on or near CCA-treated playsets and decks, and key exposure factors. Future studies should also address other sources of uncertainty in addition to parameter uncertainty, such as scenario and model uncertainty.