Urinary Excretion of Chromium Following Ingestion of Chromite-Ore Processing Residues in Humans: Implications for Biomonitoring

Biomonitoring programs for urinary chromium (Cr) typically attempt to evaluate occupational exposure via the inhalation route. This study investigated whether Cr can be detected in the urine of people following the ingestion of soils that contain relatively high concentrations of chromium in chromite ore processing residue (COPR). To evaluate the reasonableness of using urinary monitoring to assess environmental exposure, six volunteers ingested 400 mg of soil/day (low-dose group), two others ingested 2.0 g of soil/day (high-dose group) for 3 consecutive days, and one person ingested a placebo on each of 3 days. The soil and COPR mixture contained concentrations of total chromium (Cr) and hexavalent chromium [Cr(VI)] of 103 ± 20 and 9.3 ± 3.8 mg/kg, respectively. Therefore, the low-dose group ingested 41 μg Cr/day [including 3.7 μg Cr(VI)] and the high-dose group ingested 206 μg Cr/day [including 18.6 μg Cr(VI)] on each of 3 consecutive days. All urine samples were collected and analyzed individually for total Cr on the day prior to dosing, during the 3 days of dosing, and up to the first void 48 h after the last dose. No significant increases in urinary Cr excretion were found when background excretion data were compared with data following each of the 3 days of dosing or in daily mean urine concentrations of the high- vs the low-dose groups. It appears that Cr present in a soil and COPR mixture at Cr doses up to 200 μg/day is not sufficiently bioavailable for biomonitoring of urine to be informative. These results are consistent with previously published findings suggesting that incidental exposure to dusts and soils containing comparable levels of Cr will not result in increased concentrations of Cr in urine.     

The Untold Story of 50 Years of Adolescent Fertility in West Africa: A Cohort Perspective on the Quantum,Timing, and Spacing of Adolescent Childbearing

Although recent studies examine overall fertility trends in West Africa, few using advanced demographic techniques focus on adolescents. This study explores long‐term patterns of adolescent childbearing in 12 West African countries using 51 Demographic and Health Surveys covering birth cohorts that span 54 years (1940–1994). We employ classic demographic measures as well as disaggregation by early‐ (10–14 years old), middle‐ (15–17), and late adolescence (18–19). Cohort‐based estimates of total adolescent births, parity progression ratios, and rapid repeat birth probabilities reveal little change over time. Most women begin childbearing in adolescence, the progression to additional adolescent births remains common, and the incidence of rapid repeat births is high. In recent cohorts, women exit adolescence with an average of between 0.4 (Ghana) to 1.3 (Niger) births. Contrary to common assumptions, it is women commencing motherhood in early‐ and middle‐, not later adolescence, who account for most West African adolescent fertility.     

Urbanisation: an economic overview of some of the issues

"The paper presents a discussion of the economic justification for taking cities seriously, a section outlining the scale of urbanisation and some of the issues raised, a section that discusses the policy approaches, one that looks at the local agencies for the formulation and execution of policy, and a short final part on some of the implications for aid policy." The focus is on the importance of the urban sector for economic development in developing countries.     

Economic development and urbanisation

Trends in urbanization in developing countries are analyzed, with a focus on the causes of rapid urbanization and particularly on the role of the division of labor. The impact of urbanization on the process of economic development is described. The role of government and of urban planning policies is also considered.     

Obstacles for child participation in care and protection cases—why Norwegian social workers find it difficult

Although some attempts are being made to increase children's participation in Norwegian child protection cases, much needs to be done in order to comply with the participation principle in the United Nations Convention on the Rights of the Child. This paper reports on a study of factors that are likely to predict if social workers will attempt to give children an effective voice in decision making processes. 53 child protection case managers and 33 social work students participated in a questionnaire survey in which they were asked to agree or disagree with 20 statements about child participation. Statistical factor analysis was used in order to identify underlying factors in the dataset. The results suggest three main reasons for children not being allowed to participate: communication difficulties (communication factor); because child participation was not deemed necessary (participation advocacy factor); or that participation was considered inappropriate because it might be harmful (protectionism factor). This research suggests that, if we are to improve participation within the child protection system, formal regulations and guidelines need to be accompanied by a greater attention to development of social work skills in working with children through participatory processes. Copyright © 2010 John Wiley & Sons, Ltd.     

Social Class and Parenting: Classic Debates and New Understandings

Many scholars pinpoint the family as one of the most important loci of class differences and see parenting in particular as a mechanism for the reinforcement and reproduction of class variation. In this article, the authors explore the role of educational background, occupations, family resources, state surveillance, and culture in explaining how and why parenting practices vary by class backgrounds. The article reviews research that focuses on class‐based cultural norms and values, as well as research that argues that structural conditions and access to resources are more important than culture in influencing parenting norms, beliefs, and outcomes. The authors then discuss recent research that suggests that rather than seeing culture and structure as dichotomous, in fact, culture and structure are intertwined and it is through seeing them as mutually reinforcing factors that we can best make sense of class‐related parenting differences.     

Life Course Perspectives on the Links Between Poverty and Obesity During the Transition to Young Adulthood

Increasing obesity among Americans is a serious issue in the US, especially in the pediatric and young adult population. We use a longitudinal design to examine the relationship between childhood poverty/welfare receipt and obesity onset and continuity from adolescence into young adulthood using three waves of the National Longitudinal Study of Adolescent Health. We include multiple measures of disadvantage that co-occur with poverty and model potential mediating mechanisms within a life course framework. We find a significant effect of poverty/welfare receipt in childhood on obesity outcomes for females, but not for males. However, other measures of socioeconomic disadvantage such as neighborhood poverty, and low parental education are related to obesity in both males and females. Poverty may impact female obesity through the mediating effects of physical activity, inadequate sleep, skipping breakfast and certain forms of parental monitoring, while race is an important confounder of poverty’s influence. This paper highlights the important influence of poverty and other aspects of social disadvantage on obesity outcomes during this critical transition to adulthood. Implications of this research include physical activity and parenting interventions for low-income youth. In addition, governmental efforts should be made to increase physical activity opportunities in poor neighborhoods.