The impact of new technologies on human population studies

Human population studies involve clinical or epidemiological observations that associate environmental exposures with health endpoints and disease. Clearly, these are the most sought after data to support assessments of human health risk from environmental exposures. However, the foundations of many health risk assessments rest on experimental studies in rodents performed at high doses that elicit adverse outcomes, such as organ toxicity or tumors. Using the results of human studies and animal data, risk assessors define the levels of environmental exposures that may lead to disease in a portion of the population. These decisions on potential health risks are frequently based on the use of default assumptions that reflect limitations in our scientific knowledge. An important immediate goal of toxicogenomics, including proteomics and metabonomics, is to offer the possibility of making decisions affecting public health and public based on detailed toxicity, mechanistic, and exposure data in which many of the uncertainties have been eliminated. Ultimately, these global technologies will dramatically impact the practice of public health and risk assessment as applied to environmental health protection. The impact is already being felt in the practice of toxicology where animal experimentation using highly controlled dose-time parameters is possible. It is also being seen in human population studies where understanding human genetic variation and genomic reactions to specific environmental exposures is enhancing our ability to uncover the causes of variations in human response to environmental exposures. These new disciplines hold the promise of reducing the costs and time lines associated with animal and human studies designed to assess both the toxicity of environmental pollutants and efficacy of therapeutic drugs. However, as with any new science, experience must be gained before the promise can be fulfilled. Given the numbers and diversity of drugs, chemicals and environmental agents; the various species in which they are studied and the time and dose factors that are critical to the induction of beneficial and adverse effects, it is only through the development of a profound knowledge base that toxicology and environmental health can rapidly advance. The National Institute of Environmental Health Sciences (NIEHS), National Center for Toxicogenomics and its university-based Toxicogenomics Research Consortium (TRC), and resource contracts, are engaged in the development, application and standardization of the science upon which to the build such a knowledge base on Chemical Effects in Biological Systems (CEBS). In addition, the NIEHS Environmental Genome Project (EGP) is working to systematically identify and characterize common sequence polymorphisms in many genes with suspected roles in determining chemical sensitivity. The rationale of the EGP is that certain genes have a greater than average influence over human susceptibility to environmental agents. If we identify and characterize the polymorphism in those genes, we will increase our understanding of human disease susceptibility. This knowledge can be used to protect susceptible individuals from disease and to reduce adverse exposure and environmentally induced disease.     

The impact of impact studies

Summary 1. On January 1, 1970 the National Environmental Protection Act became law in the United States, and has been further strengthened by judicial interpretations. This act requires, among other things, a presentation of information to justify the effect of projects on the environment of both public and private works controlled by the permit process of the federal government, and to suggest alternatives. One of the events which influenced passage of this legislation was the Santa Barbara oil spill of January 1969.2. Insofar as the marine environment is concerned, the most significant activity related to the requirement for impact statements is the study of coastal situations where waste outfalls, atomic power plants or desalination plants may be located. Although many of the studies sponsored by industry have been cursory, the need for critical application of ecological techniques known since the classical studies ofLorenz (1863) and touched upon in brief notes byHerdman (1920) andElmhirst (1932) has become obvious through the public hearing process.3. The impact of impact studies may not only be to raise the standards of environmental studies in the sea, but also to clarify the present somewhat incoherent application by pragmatic ecologists of such debatable theoretical concepts as diversity and community stability.

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L'impact des études d'impact

Extrait Le 1ier janvier 1970 le «National Environmental Policy Act» est devenu une loi aux Etats-Unis, et a été renforcé par des dispositions judiciaires. Cette loi rend obligatoire, entre autres, la présentation d'informations concernant l'effet, sur l'environnement, des travaux publics ou privés projetés et autorisés par le gouvernement fédéral, ainsi que la suggestion de projets alternatifs. Un des évènements qui a influencé l'adoption de cette législation est le rejet de pétrole survenu à Santa Barbara en janvier 1969. Quant à l'environnement marin, la disposition la plus importante relative aux prévisions d'impact concerne l'étude des stations côtières où peuvent être situées des décharges de déchets ou des centrales nucléaires ou de désalination. Quoique beaucoup d'études entreprises par l'industrie aient été superficielles, les enquêtes publiques ont fait apparaître la nécessité d'une application critique des techniques écologiques connues depuis les travaux classiques deLorenz (1863), brièvement évoqués parHerdman (1920) etElmhirst (1932). L'impact des études d'impact pourra non seulement relever le niveau des études sur l'environnement marin, mais aussi clarifier l'application actuellement assez incohérente, par des écologistes pragmatiques, de concepts théoriques aussi contestables que ceux de la diversité ou stabilité des communités.

     

Long-term effects of malnutrition during lactation on the thyroid function of offspring.

Some studies have shown that the mother's nutritional condition may influence offspring's endocrine function through metabolic imprinting. Recently, we showed that the kind of maternal malnutrition during lactation affects adult body weight of the offspring and it is related to milk composition. We studied lactating rats fed an 8 % protein-restricted diet (PR), a control 23 % protein diet (C), and an energy-restricted diet group (ER). After weaning, all animals received a normal diet until they were 180 days of age. At this time, the animals received a single i. p. injection of (131)I and were sacrificed 2 h after the injection. Total triiodothyronine (TT3) and total thyroxin (TT4) serum concentrations were measured by enzyme immunoassay. The PR group had significantly a higher thyroid (131)I uptake, TT3 serum concentration and in TT4 serum concentration, compared to the controls. The ER group had only significantly higher TT3 serum concentration. These results showed that thyroid function regulation in adulthood may depend on maternal nutritional condition during lactation. Probably, PR group had a high thyroid function, whereas the ER group only had an increase in the deiodination of T4. The hyperthyroidism in the PR group could explain the low body weight observed in those animals.     

The impact of growth hormone on proteomic profiles: a review of mouse and adult human studies

Growth hormone (GH) is a protein that is known to stimulate postnatal growth, counter regulate insulin’s action and induce expression of insulin-like growth factor-1. GH exerts anabolic or catabolic effects depending upon on the targeted tissue. For instance, GH increases skeletal muscle and decreases adipose tissue mass. Our laboratory has spent the past two decades studying these effects, including the effects of GH excess and depletion, on the proteome of several mouse and human tissues. This review first discusses proteomic techniques that are commonly used for these types of studies. We then examine the proteomic differences found in mice with excess circulating GH (bGH mice) or mice with disruption of the GH receptor gene (GHR^?/?). We also describe the effects of increased and decreased GH action on the proteome of adult patients with either acromegaly, GH deficiency or patients after short-term GH treatment. Finally, we explain how these proteomic studies resulted in the discovery of potential biomarkers for GH action, particularly those related with the effects of GH on aging, glucose metabolism and body composition.     

The impact of paleomagnetism on paleoclimatic studies

Paleomagnetism presents the paleo-bioclimatologist for the first time with an independent determination of latitude. In combination with paleogeography a reconstruction of climatic zones for the geologic periods can be attempted by taking into account the principles underlying the present distribution of climate. This was attempted for the Permian of Europe and the Triassic, Permian and Pennsylvanian (U. Carboniferous) of North America. An extension of this method can be of great importance in future paleo-ecological and bioclimatological studies if the underlying principles of Paleomagnetism prove to be correct.     

Biogeochemistry research needs: observations from the ecosystem studies program of The National Science Foundation

This comment presents current and emerging areas of research which the U.S. National Science Foundation believes have special promise for advancing ecosystem science. These areas are: (1) major element cycle interactions; (2) trace element and organic compound controls on ecosystem dynamics; (3) the role of consumers on ecosystem dynamics; (4) ecosystem dynamics in contrasting environments; (5) landscape ecology; and (6) enhancement of theory and methodology. The Ecosystem Studies Program of the National Science Foundation has identified these as areas to be emphasized in its long range planning program (revised March, 1985). Biogeochemical studies are emphasized in many of these research priority areas.     

A method for human health impact assessment in social LCA: lessons from three case studies

Purpose

Improving human health is a long-lasting endeavour of mankind. In the field of social life cycle assessment (SLCA), the importance of human health is often highlighted, and further development of impact assessment methods has been recommended. The purpose of this article is to present a method for assessing human health impacts within SLCA.

Methods

By using a systematic combining approach, knowledge and experience about assessing human health impacts were obtained from three previously conducted case studies. The first case study was about an airbag system, the second about a catalytic converter and the third about gold jewellery. The disability-adjusted life years (DALY) indicator was used for impact assessment in all three case studies.

Results and discussion

Both positive and negative human health impacts associated with the products were identified and assessed in the three case studies. For the airbag system, avoided health impacts in the use phase outweighed health impacts during production. For the catalytic converter, whether health impacts avoided exceeded health impacts caused or not depended on which time perspective regarding impacts was employed. Gold jewellery does not help avoiding any health impacts but caused considerable health impacts when produced at a certain location. Based on experience from these case studies, a generic human health impact assessment method was developed, and a life cycle human health typology for products was developed based on the method. The method provides a basis for analysis and interpretation of health impacts along product life cycles, and it is therefore important to report both positive and negative health impacts separately for different actors.

Conclusions

The developed human health impact assessment method involves the assessment and comparison of both positive and negative human health impacts along product life cycles. In addition to the products assessed in the three case studies, we suggest additional products that could be particularly interesting to assess with the developed method, including medicines, seat belts, other conflict minerals, alcoholic beverages and products with a high chemical impact.

     

The impact of species concept on biodiversity studies

Species are defined using a variety of different operational techniques. While discussion of the various methodologies has previously been restricted mostly to taxonomists, the demarcation of species is also crucial for conservation biology. Unfortunately, different methods of diagnosing species can arrive at different entities. Most prominently, it is widely thought that use of a phylogenetic species concept may lead to recognition of a far greater number of much less inclusive units. As a result, studies of the same group of organisms can produce not only different species identities but also different species range and number of individuals. To assess the impact of different definitions on conservation issues, we collected instances from the literature where a group of organisms was categorized both under phylogenetic and nonphylogenetic concepts. Our results show a marked difference, with surveys based on a phylogenetic species concept showing more species (48%) and an associated decrease in population size and range. We discuss the serious consequences of this trend for conservation, including an apparent change in the number of endangered species, potential political fallout, and the difficulty of deciding what should be conserved.     

The evolution of the patterning of human lactation: A comparative perspective

Some four decades ago, Jeanne Altmann started her detailed field studies of baboon mothers and their infants with a focus on the behavioral ecology of maternal reproductive investment. 1 Around the same time, Sarah Hrdy studied langur mothers and their infants, focusing on the influence of the social environment on a female's reproductive options and decisions. 2 Their pioneering work has inspired many subsequent studies of female primate reproduction in its natural context and shaped our own work on primate mothers.     

The impact of sex and sex hormones on lung physiology and disease: lessons from animal studies

Numerous animal studies have revealed significant effects of sex and sex hormones on normal lung development, lung physiology, and various lung diseases. The primary goal of this review is to summarize knowledge to date on the effects of sex and sex hormones on lung development, physiology, and disease in animals. Specific emphasis will be placed on fibrosis, allergic airway disease, acute lung injury models, respiratory infection, and lung toxicology studies.     

The application of the herbicide bromoxynil to a model soil-derived bacterial community: impact on degradation and community structure

AIMS: Bromoxynil degradation by soil micro-organisms has been shown to be co-oxidative in character. In this study, we investigate both the impact of the application of increasing bromoxynil concentrations on soil-derived bacterial communities and how these changes are reflected in the degradation of the compound. Our aim was to test the hypothesis that the addition of bromoxynil to a soil-derived bacterial community, and the availability of a readily utilizable carbon source would have an impact on bromoxynil degradation, and that would be reflected in the bacteria present in the soil community. METHODS AND RESULTS: Degradation of bromoxynil was observed in soil-derived communities containing 15 mg l(-1), but not 50 mg l(-1) of the compound, unless glucose was added. This suggests that the addition of carbon stimulates co-oxidative bromoxynil degradation by the members of the bacterial community. Measurable changes in the bacterial community indicated that the addition of bromoxynil led to deterministic selection on the bacterial population, i.e. the communities observed arise through the selection of specific micro-organisms that are best adapted to the conditions in the soil. The addition of bromoxynil was also shown to have a negative impact on the presence of alpha and gamma-proteobacteria in the soil community. CONCLUSION: Bromoxynil degradation is significantly inhibited in bacterial soil communities in the absence of readily accessible carbon. The application of bromoxynil appears to exert deterministic selection on the bacterial community. SIGNIFICANCE AND IMPACT OF THE STUDY: This study highlights the effects of increasing bromoxynil concentrations on a model bacterial population derived from soil. Soil communities show qualitative and quantitative differences to bromoxynil application depending on the availability of organic carbon. These findings might have implications for the persistence of bromoxynil in agricultural soils.     

Herbivoran impact on phytoplankton community structure

An enclosure experiment was conducted to assess the effects of a zooplankton elimination on the structure of a phytoplankton community. Phytoplankton biomass and production were higher in grazer-free enclosures, while the productivity per unit biovolume was lower. Exclusion of zooplankton favoured the majority of algal species, especially chrysophyceans (Dinobryon spp.) and the diatom Rhizosolenia, while mucilagineous green-algae were disfavoured. Middle sized algae (ESD 15–50 µm) and those with the largest Surface Area/Volume ratio were proportionally most favoured by the elimination of grazers.These differences in phytoplankton community structure are discussed in relation to effects of direct selective grazing and nutrient recycling by zooplankton. Some differences, as the immediate positive response of Dinobryon and Rhizosolenia, are probably caused by grazing release, while others, e.g. the response of mucilagineous species, might be caused by changed competitive relationships between the algae.     

Household and community socioeconomic influences on early childhood malnutrition in Africa

This paper uses multilevel modelling and Demographic and Health Survey data from five African countries to investigate the relative contributions of compositional and contextual effects of socioeconomic status and place of residence in perpetuating differences in the prevalence of malnutrition among children in Africa. It finds that community clustering of childhood malnutrition is accounted for by contextual effects over and above likely compositional effects, that urban-rural differentials are mainly explained by the socioeconomic status of communities and households, that childhood malnutrition occurs more frequently among children from poorer households and/or poorer communities and that living in deprived communities has an independent effect in some instances. This study also reveals that socioeconomic inequalities in childhood malnutrition are more pronounced in urban centres than in rural areas.     

The impact of arthropods on fungal community structure in Lascaux Cave

Aims:  To determine the major components of the fungal population present in Lascaux Cave, France. The ceiling, walls, sediments and soil were colonized by Fusarium solani in 2001 and later, in 2006, black stains appeared. However, the origin of the successive fungal invasions is unknown as well as the ecology of the cave.
Methods and Results:  The primers nu-SSU-0817F and nu-SSU-1536R were used for the direct amplification of fungal 18S-rDNA sequences from 11 samples. A total of 607 clones were retrieved. Eight out of the ten most abundant phylotypes corresponded to fungi associated with arthropods and represented about 50% of the clones.
Conclusions:  Entomophilous fungi play an important role in the cave and arthropods contribute to the dispersion of spores and fungal development.
Significance and Impact of the Study:  Choosing appropriate targets for control of fungal dispersal is dependent on knowing the causes of fungal colonization. A control of the arthropod populations seems to be a need in order to protect the rock art paintings in Lascaux Cave.