Influence of environment on insulin sensitivity

Genetic and environmental factors influence insulin sensitivity (IS) during one's lifetime. Actually, uterine environment may affect IS at birth and later in life. In particular, various exogenous toxic substances, coupled to a genetic predisposition, may remarkably influence the regulation of the hypothalamus–hypophysis–adrenal gland axis, and the production or the activity of insulin, cerebral incretins, pro-inflammatory cytokines, and placental hormones. Owing to this reaction against environmental injuries, fetal growth and endocrine system development may be impaired, leading to low or large birth weight, or prematurity. Reduced growth in early life has been related to insulin resistance, which can be silent for years and evident in predisposed adults. The incidence of type 2 diabetes mellitus and obesity associated with sedentary lifestyle patterns and inadequate dieting behaviors in children and adolescents has rapidly increased during the last decade.Recent evidences suggest that the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-? (PPAR-?) gene and the angiotensin converting enzyme (ACE) I/D gene polymorphism combined with environmental factors, such as phthalates interfering with the post receptorial action of insulin, alter insulin-sensible tissues. Therefore, IS, deriving from a complex interaction between genotype and environment, may change during life and depends on previous metabolic control, which is a sort of metabolic memory. The goal for the future is preventing the complications associated with impaired IS through the control of exogenous factors and the use of drugs selectively effective on its pathogenesis.     

Environmental and lifestyle factors affect benzene uptake biomonitoring of residents near a petrochemical plant

Background

We monitored urinary benzene excretion to examine factors affecting benzene uptake in a sample of the general population living near a petrochemical plant.

Methods

Our study population included 143 subjects: 33 petrochemical plant workers (W) with low level occupational benzene exposure; 30 residents in a small town 2 km from the plant (2kmR); 26 residents in a second small town located 2 to 4 km from the plant (4kmR); and 54 urban residents 25 km from the plant (25kmR). Exposure to benzene was evaluated by personal air sampling during one work-shift for the W group, and from 8.00 to 20:00 for general population subgroups, and by urinary benzene (BEN-U).

Results

Median airborne benzene exposure was 25, 9, 7 and 6 μg/m³ benzene among the W, 2kmR, 4kmR, and 25kmR subgroups, respectively; the highest level was found among the workers, while there was no significant difference among the other groups. Median BEN-U was 2 to 14-fold higher in smokers compared to non-smokers; among non-smokers BEN-U was the highest in W (median 236 ng/L), and lower in the 2kmR (48 ng/L) and 4kmR (63 ng/L) subgroups than in the 25kmR (120 ng/L) subgroup. A multiple linear regression analysis, explaining up to 73% of BEN-U variability, confirmed that active smoking and airborne benzene most strongly affected BEN-U. Among the non-smoking, non-occupationally exposed study subjects, a positive association was found between BEN-U and the distance of residence from the plant. This association was explained by increased exposure to urban traffic emissions in the study group residing at a greater distance from the plant. Environmental tobacco smoke had a marginally positive role.

Conclusion

Among factors affecting benzene uptake in non-occupationally exposed individuals, urban residence contributes to benzene exposure more than residing in close proximity to a petrochemical plant.     

Herbicide losses in runoff events from a field with a low slope: role of a vegetative filter strip

Herbicide runoff and the effects of a narrow vegetative filter strip (VFS) were studied on an arable field in the low-lying plains of the Veneto Region (north-east Italy). Cultivated plots were compared with and without a 6m wide VFS composed of trees, shrubs and grass. Natural and simulated runoff were monitored during 2000 and 2001. Herbicides applied on the field were: metolachlor (2184-2254 g ha(-1)), terbuthylazine (1000-1127 g ha(-1)) and isoproturon (1000 g ha(-1)). The VFS reduced both runoff depth (10.2-91.2%) and herbicide losses (85.7-97.9%) in the monitored rainfall events. Total herbicide loss with runoff was low (0.69-3.98 g ha(-1) without VFS, less than 0.27 g ha(-1) with VFS), but concentrations were sometimes very high, especially of terbuthylazine and isoproturon during the first events after treatment. In these events there was a high probability of exceeding the ecotoxicological endpoint for algae, but the VFS helped to reduce the potential risk. Two VFS effectiveness mechanisms were identified: (i) dilution, and (ii) a "sponge-like" effect, which temporarily trapped chemicals inside the VFS before releasing them.     

Concentrations of trace elements in tissues of loggerhead turtles (Caretta caretta) from the Tyrrhenian and the Ionian coastlines (Calabria,Italy)

Environmental Science and Pollution Research - Toxic trace elements from both, natural and anthropogenic origin, pose a threat to aquatic environments and marine wildlife due to their long-range...     

Correlates of pro-sustainability orientation: The affinity towards diversity

The concept of affinity towards diversity (ATD) is introduced and illustrated with two studies on the psychological drivers of pro-sustainability orientation and environmentally friendly behaviors. In light of the importance that biological and social ecological sciences assign to diversity within socio-ecological systems, ATD was conceptualized as an individual predisposition to appreciate the dynamic variety of human–nature interactions in everyday life situations. ATD implies valuing and liking biological and socio-cultural diversity, more than simply being respectful before or accepting differences in the social and physical contexts. Two different samples of Mexicans responded to a series of scales, one of them assessing ATD. The scale exhibited an acceptable level of internal consistency and it also showed construct validity, according to the results of two structural equation models. A first study showed that ATD significantly and negatively covaries with a scale of intolerance, and positively covaries with a measure of environmentally friendly behavior. A second study revealed also that ATD, together with other psychological factors (future orientation, altruism, emotions towards nature), forms the basis for a pro-sustainability orientation which, in turn, predicts environmentally friendly behaviors.     

Reconstruction of the environmental evolution of a Sicilian saltmarsh (Italy)

The present study deals with the reconstruction of the environmental evolution of a Trapani saltmarsh (southwestern Sicily, Italy) by combining different analytical approaches such as metal content evaluation, low-field nuclear magnetic resonance (NMR) relaxometry, and benthic foraminifera identification. A 41 cm core was collected in the sediments of a Trapani saltmarsh (southwestern Sicily, Italy) at a water depth of about 50 cm. Different time intervals were recognized, each characterized by peculiar features that testify different environmental conditions. In particular, the bottom layers of the sediment core (41–28 cm) comprised the lowest amount of mud fraction, only some selected metals, and the lowest foraminiferal density. Here, co-occurrence of abundant microcrystals of gypsum and Ammonia tepida is indicative of hyper-saline conditions. In the sediments from 28 to 6 cm, mud fraction and number of metal elements resulted higher due to the increase of the anthropogenic pressure. The sediments in the last time interval, corresponding to the environmental recovery of the saltmarsh, showed an increase of foraminiferal density, a decrease of the mud fraction, and a trend in the metal concentration attributable to the protection policy applied since 1990. NMR relaxometry parameters highlighted the changes of sediment chemical–physical heterogeneity going from the bottom to the top of the core. These heterogeneities have been related to the different intervals recognized as aforementioned. The present study highlights how the anthropogenic pressure modifies the environmental conditions of a transitional ecosystem like saltmarshes.     

Fractal and multifractal approach to environmental pollution

A few case studies will be presented involving both radioactive and chemical pollution at small, medium, and large space-time scales. Reported are recent advances in the field of environmental pollution involving the use of fractals and multifractals. The mathematical tools proposed here may offer new perspectives for investigating many of the problems of nonlinear variability which commonly arise when dealing with pollutants, such as the presence of outliers and the sparseness of the sampling networks. They may also lead to a simplification of the models adopted for studying natural phenomena, thanks to a scaling approach. Finally, they may provide parameters whose values are directly related to the nonlinear dynamics involved in the pollutant distribution in the environment which, in turn, may be relevant for computer simulation and epidemiological or risk assessment purposes.