Hydrobiogeochemistry of two catchments in Brazil under forest recovery in an Environmental Services Payment program.

Abstract: We investigated the fluvial geochemistry of two catchments at different stages in the forest recovery process which have been a focus of an Environmental Services Payment (ESP) program in Brazil. The Posses (PS) and Salto de Cima (SC) catchments (1200 ha and 1500 ha, respectively) are situated in the municipality of Extrema, Minas Gerais state. Their streams flow into the Jaguari River that supplies part of the water demand of the São Paulo metropolitan area. Samples were collected for chemical analysis and physical-chemical field measures every 2 weeks from January to December 2017. An important pollution point source was discovered in the PS stream related to bovine urine and feces, as well another unidentified source that can be related to a small food processing industry and/or a small fish farm. At the SC stream, on the other hand, there was clear evidence of domestic sewage input. This preliminary study confirmed a limited improvement of the stream water quality in response to recovery of the forest vegetation. Therefore, we recommend that in addition to enhanced monitoring to help distinguish biogeochemical sources and the benefits of land conservation practices, the ESP program should consider controlling point source pollution to accomplish its purpose

Pre-flight qualification tests of the Mini-EUSO telescope engineering model

International audienceMini-EUSO is part of the JEM-EUSO program and operates on board the International Space Station (ISS). It is a UV-telescope with single-photon counting capability looking at nighttime downwards to the Earth through a nadir-facing UV-transparent window. As part of the pre-flight tests, the Mini-EUSO engineering model, a telescope with 1/9 of the original focal surface and a lens of 2.5 cm diameter, has been built and tested. Tests of the Mini-EUSO engineering model have been made in laboratory and in open-sky conditions. Laboratory tests have been performed at the TurLab facility, located at the Physics Department of the University of Turin, equipped with a rotating tank containing different types of materials and light sources. In this way, the configuration for the observation of the Earth from space was emulated, including the Mini-EUSO trigger schemes. In addition to the qualification and calibration tests, the Mini-EUSO engineering model has also been used to evaluate the possibility of using a JEM-EUSO-type detector for applications such as observation of space debris. Furthermore, observations in open-sky conditions allowed the studies of natural light sources such as stars, meteors, planets, and artificial light sources such as airplanes, satellites reflecting the sunlight, and city lights. Most of these targets could be detected also with Mini-EUSO. In this paper, the tests in laboratory and in open-sky conditions are reported, as well as the obtained results. In addition, the contribution that such tests provided to foresee and improve the performance of Mini-EUSO on board the ISS is discussed

Biomonitoring of complex occupational exposures to carcinogens: The case of sewage workers in Paris

<p>Abstract</p> <p>Background</p> <p>Sewage workers provide an essential service in the protection of public and environmental health. However, they are exposed to varied mixtures of chemicals; some are known or suspected to be genotoxics or carcinogens. Thus, trying to relate adverse outcomes to single toxicant is inappropriate. We aim to investigate if sewage workers are at increased carcinogenic risk as evaluated by biomarkers of exposure and early biological effects.</p> <p>Methods/design</p> <p>This cross sectional study will compare exposed sewage workers to non-exposed office workers. Both are voluntaries from Paris municipality, males, aged (20–60) years, non-smokers since at least six months, with no history of chronic or recent illness, and have similar socioeconomic status. After at least 3 days of consecutive work, blood sample and a 24-hour urine will be collected. A caffeine test will be performed, by administering coffee and collecting urines three hours after. Subjects will fill in self-administered questionnaires; one covering the professional and lifestyle habits while the a second one is alimentary. The blood sample will be used to assess DNA adducts in peripheral lymphocytes. The 24-hour urine to assess urinary 8-oxo-7, 8-dihydro-2'-deoxy-Guanosine (8-oxo-dG), and the in vitro genotoxicity tests (comet and micronucleus) using HeLa S3 or HepG2 cells. In parallel, occupational air sampling will be conducted for some Polycyclic Aromatic Hydrocarbons and Volatile Organic Compounds. A weekly sampling chronology at the offices of occupational medicine in Paris city during the regular medical visits will be followed. This protocol has been accepted by the French Est III Ethical Comitee with the number 2007-A00685-48.</p> <p>Discussion</p> <p>Biomarkers of exposure and of early biological effects may help overcome the limitations of environmental exposure assessment in very complex occupational or environmental settings.</p

Exposure levels and cytochrome P450 1A2 activity, but not N-acetyltransferase, glutathione S-transferase (GST) M1 and T1, influence urinary mutagen excretion in smokers

We investigated the polymorphic enzymes cytochrome P450 1A2 (CYP1A2), N-acetyltransferase (NAT2), glutathione S-transferase (GST) M1 (GSTM1), and T1 (GSTT1) in relation to cigarette smoking-associated urinary mutagenicity detected on YG1024 Salmonella typhimurium strain with S9 mix in 97 smokers. In each subject, cigarette smoke intake was checked by analysis of urinary nicotine plus its metabolites. NAT2 and CYP1A2 phenotypes were determined by the molar ratio of urinary caffeine metabolites detected by high-performance liquid chromatography, and GSTT1 and GSTM1 genotypes were determined by PCR. An increase in urinary mutagenicity was significantly related to levels of exposure to cigarette smoke and CYP1A2 N-hydroxylation activity (linear multiple regression analysis t = 4.51 and P < 0.001 and t = 3.09 and P = 0.003; F = 6.31, P < 0.001). Urinary mutagenicity was significantly higher in CYP1A2 extensive metabolizer smokers (n = 49) than in CYP1A2 poor metabolizer ones (n = 48; 2176 +/- 1525 versus 1384 +/- 1206 revertants/mmol creatinine, Mann-Whitney U-test, z = 2.65, P < 0.001). The highest mutagenic activity was seen in subjects CYP1A2 extensive metabolizer/NAT2 slow acetylators (n = 29) with respect to the other phenotype combinations (n = 68; 2392 +/- 1660 versus 1525 +/- 1238 revertants/mmol creatinine, Mann-Whitney U-test, z = 2.37, P = 0.017). NAT2 acetylation activity was slightly but inversely related to urinary mutagenicity, and the association was not significant. No effect of GSTM1 and GSTT1 genotypes in lowering (detoxifying) urinary mutagens was found. The significant enhancement of urinary mutagenicity associated with increased CYP1A2 activity, as already seen for diet-caused urinary mutagenicity, allows for many analogies between the process of mutagen formation derived from cooked meat and that from cigarette smoke condensate. In conclusion, the intensity of tobacco smoke exposure, modulated by CYP1A2 activity, is the major determinant of mutagenic urine among smokers, whereas GSTM1 and GSTT1 genotypes have no influence on this biomarker. This study suggests that CYP1A2 should definitely be determined in future studies involving urinary mutagenicity in cases in which smoking is a factor

Tobacco smoke exposure indicators and urinary mutagenicity.

In this study, the correlation of indicators of external (i.e. mean daily intake of condensate, nicotine, tobacco and tobacco proteins, and daily number of cigarettes smoked) and of internal tobacco-smoke exposure (i.e. urinary 1-pyrenol, nicotine and its metabolites and trans,trans-muconic acid) with urinary mutagenicity, detected on YG1024 Salmonella typhimurium strain with S9, were examined in 118 smokers. An increase in urinary mutagenicity was clearly significantly correlated with each external and internal indicators of exposure to tobacco smoke (correlation coefficient (r) ranging between 0.22 and 0.54, P<0.01), with a greater extent in the case of indicators of internal dose. In multiple regression analysis, among the indicators of external exposure, daily tobacco intake was the only variable significantly associated with urinary mutagenicity (t=2.47, P=0.015, with partial contribution to r(2)=5.15%). Instead, when all indicators of exposure (external and internal) were considered in the analysis, the influence of urinary 1-pyrenol on urinary mutagenicity was predominant, followed by those of urinary trans,trans-muconic acid and nicotine plus metabolites (t=4.63, 2.73 and 2.08, P<0.001, P=0.002 and 0.04, with partial contribution to r(2)=17.0, 6.66 and 3.96%, respectively), with no influence at all of external tobacco-smoke exposure indicators. In conclusion, our results show that indicators of internal dose are better correlated with formation of mutagens in urine of smokers. Among these, the best indicator was urinary 1-pyrenol and this result designates the combustion processes of tobacco as the determining step for the formation of urinary mutagens. However, as these biomarkers cannot be analysed the amount of daily tobacco intake represent the best valuable index of external (presumptive) exposure to tobacco-smoke genotoxins