Aging and the Environment: A Research Framework

The rapid growth in the number of older Americans has many implications for public health, including the need to better understand the risks posed to older adults by environmental exposures. Biologic capacity declines with normal aging; this may be exacerbated in individuals with pre-existing health conditions. This decline can result in compromised pharmacokinetic and pharmacodynamic responses to environmental exposures encountered in daily activities. In recognition of this issue, the U.S. Environmental Protection Agency (EPA) is developing a research agenda on the environment and older adults. The U.S. EPA proposes to apply an environmental public health paradigm to better understand the relationships between external pollution sources → human exposures → internal dose → early biologic effect → adverse health effects for older adults. The initial challenge will be using information about aging-related changes in exposure, pharmacokinetic, and pharmacodynamic factors to identify susceptible subgroups within the diverse population of older adults. These changes may interact with specific diseases of aging or medications used to treat these conditions. Constructs such as “frailty” may help to capture some of the diversity in the older adult population. Data are needed regarding a) behavior/activity patterns and exposure to the pollutants in the microenvironments of older adults; b) changes in absorption, distribution, metabolism, and excretion with aging; c) alterations in reserve capacity that alter the body’s ability to compensate for the effects of environmental exposures; and d) strategies for effective communication of risk and risk reduction methods to older individuals and communities. This article summarizes the U.S. EPA’s development of a framework to address and prioritize the exposure, health effects, and risk communications concerns for the U.S. EPA’s evolving research program on older adults as a susceptible subpopulation

Chemical Methods for Determination of Hydroxylated Metabolites of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls in Biological Material

U ovome preglednom radu prikazani su postupci analize hidroksiliranih metabolita policikličkih aromatskih ugljikovodika i poliklorbifenila u ljudima i životinjama. Ti metaboliti služe kao biomarkeri izloženosti ljudi i životinja navedenim zagađivalima, no neki od njih i sami posjeduju toksična svojstva. Analiziraju se najčešće u urinu koji je kao uzorak najdostupniji, ali se isto tako mogu analizirati i u ljudskoj, odnosno životinjskoj jetri, žuči i masnom tkivu. Analiza metabolita aromatskih zagađivala važna je zbog određivanja biodostupnosti aromatskih zagađivala, njihove potencijalne toksičnosti u ljudskom organizmu, ali i zbog toksičnosti samih metabolita. Napredak analitičkih metoda omogućio je simultanu analizu velikog broja metabolita u uzorcima. Nove tehnike ekstrakcije i selektivnije i preciznije kvalitativne i kvantitativne analize omogućuju detekciju vrlo niskih koncentracija metabolita. Pri tome dodatnu prednost imaju jednostavne tehnike koje zahtijevaju manje kemikalija i vremena za analizu.This review presents methods for the analysis of hydroxylated metabolites of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in humans and animals. These metabolites serve as biomarkers of human and animal exposure to the mentioned pollutants, but some metabolites also have toxic properties. Most are analysed in urine, which is the most accessible sample, but they can also be analysed in human and animal liver, bile, and adipose tissue. Their analysis is important for assessing bioavailability of aromatic pollutants and their toxicity in human organism, but also the toxicity of metabolites themselves. Advancements in analytical methods have made it possible to analyse multiple metabolites in a sample at the same time. New extraction techniques and more precise and selective qualitative and quantitative analyses can now detect very low metabolite oncentrations. An extra advantage is that these simple techniques require less chemicals and time

Polychlorinated biphenyl congener patterns in tissues from a selection of British birds.

A large selection of polychlorinated biphenyl (PCB) congeners was determined in tissues from several British bird species including three sea birds, four birds of prey, and herons (Ardea cinerea). The congener “signatures” were consistent between different tissues of the same individual, but varied within and between species. Congeners 138, 153, and 180 were dominant in most samples. Nevertheless, ∑PCB values were wide ranging (0.02–105 μg/g wet weight) and also differed considerably in subsamples of different tissues from individual birds. Applying recently reported toxicity equivalency factors (TEFs) for non-ortho, mono-ortho, and di-ortho substituted PCBs to liver concentrations of such congeners, it appears that the mono-ortho congeners 105 and 118 make a high contribution to TEFs when their toxicities are weighted by concentration. The study highlights that caution is needed when interpreting data on contaminants in wildlife, but suggests that careful sampling will reduce the many variables which can give rise to differing congener patterns and ∑PCB values