scholarly journals Human Breathable Air in a Mediterranean Forest: Characterization of Monoterpene Concentrations under the Canopy

Author(s):  
Albert Bach ◽  
Ana Maria Yáñez-Serrano ◽  
Joan Llusià ◽  
Iolanda Filella ◽  
Roser Maneja ◽  
...  

Monoterpenes have been identified as potential determinants of the human health effects induced by forest exposure. The present study characterizes the total monoterpene concentrations at nose height in a Mediterranean Holm oak forest located in North-East Iberian Peninsula during the annual emission peak (summer and autumn: June to November) using a Proton Transfer Reaction–Mass Spectrometry (PTR-MS). Results show a strong variability of the total monoterpene concentrations in season and daytime. The concentration peak appears during July and August. These two months displayed two average maxima in their diel cycles: One during early morning (from 6:00 to 8:00, 0.30 ppbv for July and 0.41 ppbv for August) and another one at early afternoon (from 13:00 to 15:00, 0.27 ppbv during July and 0.32 ppbv during August). Monoterpene concentrations were strongly related with the temperature (exponentially) and solar radiation (rectangular hyperbolic relationship). The concentrations registered here are similar or higher than in previous ex situ studies showcasing the effects of forests on human health. These findings provide relevant data for the scientific and healthcare community by improving the understanding of monoterpene dynamics at nose height and suggesting further research on the effects of forests on human health, particularly in the Mediterranean region.

2016 ◽  
Vol 16 (11) ◽  
pp. 7171-7194 ◽  
Author(s):  
Simon Schallhart ◽  
Pekka Rantala ◽  
Eiko Nemitz ◽  
Ditte Taipale ◽  
Ralf Tillmann ◽  
...  

Abstract. Recently, the number and amount of biogenically emitted volatile organic compounds (VOCs) has been discussed in great detail. Depending on the ecosystem, the published number varies between a dozen and several hundred compounds. We present ecosystem exchange fluxes from a mixed oak–hornbeam forest in the Po Valley, Italy. The fluxes were measured by a proton transfer reaction-time-of-flight (PTR-ToF) mass spectrometer and calculated using the eddy covariance (EC) method. Detectable fluxes were observed for up to 29 compounds, dominated by isoprene, which comprised over 60 % of the total upward flux (on a molar basis). The daily average of the total VOC upward flux was 10.4 nmol m−2 s−1. Methanol had the highest concentration and accounted for the largest downward flux. Methanol seemed to be deposited to dew, as the downward flux happened in the early morning, right after the calculated surface temperature came closest to the calculated dew point temperature.We estimated that up to 30 % of the upward flux of methyl vinyl ketone (MVK) and methacrolein (MACR) originated from atmospheric oxidation of isoprene. A comparison between two methods for the flux detection (manual and automated) was made. Their respective advantages and disadvantages were discussed and the differences in their results shown. Both provide comparable results.


2015 ◽  
Vol 15 (19) ◽  
pp. 27627-27673 ◽  
Author(s):  
S. Schallhart ◽  
P. Rantala ◽  
E. Nemitz ◽  
D. Mogensen ◽  
R. Tillmann ◽  
...  

Abstract. Recently, the number and amount of biogenically emitted volatile organic compounds (VOCs) has been discussed vigorously. Depending on the ecosystem the published number varies between a dozen and several hundred compounds. We present ecosystem exchange fluxes from a mixed oak-hornbeam forest in the Po Valley, Italy. The fluxes were measured by a proton transfer reaction-time-of-flight (PTR-ToF) mass spectrometer and calculated by the eddy covariance (EC) method. Detectable fluxes were observed for twelve compounds, dominated by isoprene, which comprised over 65 % of the total flux emission. The daily average of the total VOC emission was 9.5 nmol m-2 s-1. Methanol had the highest concentration and accounted for the largest deposition. Methanol seemed to be deposited to dew, as the deposition happened in the early morning, right after the calculated surface temperature came closest to the calculated dew point temperature. We estimated that up to 27 % of the upward flux of methyl vinyl ketone (MVK) and methacrolein (MACR) originated from atmospheric oxidation of isoprene. A comparison between two flux detection methods (classical/visual and automated) was made. Their respective advantages and disadvantages were discussed and the differences in their results shown. Both provide comparable results; however we recommend the automated method with a compound filter, which combines the fast analysis and better flux detection, without the overestimation due to double counting.


2019 ◽  
Author(s):  
Chem Int

Liquid effluents discharged by hospitals may contain chemical and biological contaminants whose main source is the different substances used for the treatment of patients. This type of rejection can present a sanitary potentially dangerous risk for human health and can provoke a strong degradation of diverse environmental compartments mainly water and soils. The present study focuses on the quality of the liquid effluents of Hassani Abdelkader’s hospital of Sidi Bel-Abbes (West of Algeria). The results reveal a significant chemical pollution (COD: 879 mgO2/L, BOD5: 850 mgO2/L, NH4+ : 47.9 mg/l, NO2- : 4.2 mg/l, NO3- : 56.8 mg/l with respect to WHO standard of 90 mgO2/L, 30 mgO2/L, 0.5 mg/l, 1 mg/l and 1 mg/l respectively). However, these effluents are biodegradable since the ratio COD/BOD5 do not exceeded the value of 2 in almost all samples. The presence of pathogen germs is put into evidence such as pseudomonas, the clostridium, the staphylococcus, the fecal coliforms and fecal streptococcus. These results show that the direct discharge of these effluents constitutes a major threat to human health and the environment.


Author(s):  
Ana Veruska Cruz da Silva ◽  
Jéssica Monalisa S. P. Oliveira ◽  
Milena Nascimento Cardoso ◽  
Ana Letícia Sirqueira Nascimento ◽  
Tássia Fernanda S. N. Soares ◽  
...  

2016 ◽  
Vol 28 (6) ◽  
pp. 965-970
Author(s):  
Ved Prakash Kumar ◽  
Anupam Shrivastwa ◽  
Parag Nigam ◽  
Dhyanendra Kumar ◽  
Surendra Prakash Goyal

2009 ◽  
Vol 7 (S1) ◽  
pp. S75-S93 ◽  
Author(s):  
Mark D. Sobsey ◽  
Suresh D. Pillai

A consideration of available evidence for some known and well-characterized waterborne pathogens suggests that the diversity of pathogen virulence mechanisms and properties is too great to specifically predict the emergence and future human health impacts of new waterborne pathogens. However, some future emerging pathogens are existing microbes that will be discovered to cause disease. Some will arise from existing ones by either predictable evolutionary and adaptation changes or by unpredictable changes involving a variety of biotic and abiotic mechanisms. Many, and perhaps most, emerging waterborne human pathogens will be zoonotic agents or come from other non-human reservoirs. The emergence of some waterborne pathogens will be related to antibiotic use, resulting in emerging antibiotic-resistant waterborne pathogens. Reliably predicting pathogen emergence and human health effects based on VFARs or other properties of microbes and their hosts is not possible at this time. This is because of (1) the diversity of microbes and their virulence and pathogenicity properties, (2) their ability to change unpredictably, (3) their intimate and diverse interrelationships with a myriad of hosts and dynamic natural and anthropogenic environments and (4) the subtle variations in the immune status of individuals. The best available approach to predicting waterborne pathogen emergence is through vigilant use of microbial, infectious disease and epidemiological surveillance. Understanding the microbial metagenome of the human body can also lead to a better understanding of how we define and characterize pathogens, commensals and opportunists.


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