Biological activity of Dittrichia viscosa (L.) Greuter extracts against adult Sitophilus granarius (L.) (Coleoptera, Curculionidae) and identification of active compounds.

Dittrichia viscosa (L.) Greuter, a perennial weed of the Mediterranean area, was reported to be source of active substances. Here, by means of both ingestion and contact assays, the biological activity of three different extracts (n-hexane, methanol, and distilled water) of D. viscosa aerial part has been evaluated against Sitophilus granarius (L.) adults, an important pest of stored grains. Ingestion assays showed negligible mortality and food deterrence for all the extracts, whereas only a slight reduction of some nutritional parameters (relative growth rate, relative consumption rate, food efficiency conversion) was recorded for water extract. High contact toxicity was found only for the n-hexane extract (24 h median lethal dose LD50 = 53.20 µg/adult). This extract was further subfractioned by silica gel column chromatography and then by thin layer chromatography. Further contact toxicity bioassays highlighted two active subfractions which were analyzed by GC-MS. This revealed the occurrence, in both subfractions, of two major peaks that were identified as α- and γ- costic acid isomers. Moreover, D. viscosa active subfractions, did not cause acetylcholinesterase (AChE) inhibition; therefore, in the light of progressive limitation of compounds acting by this mechanism of action, D. viscosa represents a promising eco-sustainable source of natural products for pest control.

Influence of air pollution on chronic obstructive respiratory diseases: comparison between city (Rome) and hillcountry environments and climates.

Chronic Obstructive Pulmonary Diseases (COPDs) constitute a social problem of widespread interest. These diseases increase slowly and constantly. Air pollution and its impact on public health continually repropose certain absolute priorities, such as the pin-pointing of strategies to control the pollution sources, the planning of observational studies and the epidemic control. This work shows that a climate marked by always windy weather and low humidity and with low chemical pollutant concentrations (Pietracupa; Molise, Italy) is connected to smaller prevalence of COPDs in comparison with big cities like Rome. Living in non-polluted areas, the benefits of a healthy climate in terms of an improvement in breathing and bronchial hyperactivity reduction, may only in part be backed up by epidemic evidence; however, they are a solid base on which to build definite research projects which can effectively validate it even from an experimental point of view supported by statistics.

Remote sensing measurements for evaluation of air quality in an urban area.

The Differential Optical Absorption Spectrometry (DOAS) is a remote-sensing technique finding greater consents in these last years. The analytical principle of the DOAS system is based on the light absorption in the near-UV and Vis regions of those pollutants with fine vibrational structures such as SO2, NO2, O3, nitrous acid, formaldehyde, benzene, toluene, etc.. The relationship among the adsorbed light intensity and the xompound concentrations is ruled by the Lambert-Beer's law. The DOAS analysis allows to study and to interpretate the complex mechanisms of the formation and transformation of the pollutants and particularly of those of secondary origin. In this paper we have reported and discussed the behaviors of NO2, O3, HNO2, formaldehyde, benzene and toluene measured by this system during the 2000--2003 period in the Rome area (an area highly influenced by anthropogenic sources) and in Pietracupa (Molise) area (considered as remote site). The results show how the DOAS system highlight very well the secondary pollution evolution; this, described by the profiles of NO2 and O3 being at the same time products and precursors of the photochemical smog, is not influenced by the emission flow intensity and consequently assumes homogeneous values in the whole urban area.