The Chromium issue in soils of the leather tannery district in Italy.

pubblicato su CD-Rom (EGU06-A-02354

The chromium issue in soils of the leather tannery district in Italy

Among heavy metals, up to now chromium has received little attention. The reasons for this lack of interest are diverse. One is that Cr was considered a “ local source ” contaminant, thus constituting a non-widespread environmental problem. A second reason is that the dominant naturally occurring form of chromium, Cr2 O3, is considered essentially immobile in the environment, in contrast with the highly mobile and toxic Cr(VI). Based on these assumptions, we have started a research program aimed at assessing the actual chromium accumulation in soils and plants of a tannery industrial district in NE Italy. Further objectives of our study were: - to highlight possible contamination of soils, plants and waters; - to ascertain the potential risk to human health. Large differences in Cr concentration were observed in the area investigated, with a very scattered distribution. Mean Cr concentration in soils is 210 mg/kg (range 50 – 10,000). Most of the investigated sites present surface Cr concentrations higher than subsurface, suggesting local sources of Cr to be responsible for soil contamination. Chromium concentrations in selected plants ( Taraxacum officinale , Plantago lanceolata) present wide ranges in both the species examined, with little translocation from roots to leaves (barrier effect). To determine the groundwater pollution hazard in the surveyed district, we have compared the soil Cr concentration with the soil vulnerability map. Surface soils having the highest Cr concentration correspond to sites with very high to high vulnerability. Therefore, considering the present soil Cr concentrations and the pollution hazard, precaution and control acts are needed, in order to avoid more damage to land and waters. Moreover, considering all the above items, hazard for human health by direct contact with soil, ingestion, and inhalation should be taken in consideration by decision makers

The Chromium issue in soils of the leather tannery district in Italy.

pubblicato su CD-Rom (EGU06-A-02354

Essential oil composition of Stachys sylvatica L. from Italy.

ABSTRACT: Slachys sylvatica L. is a perennial herb belonging to the genus Stachys, widespread in all the Italian peninsula in mountainous and moist places. The whole plant emanates an unpleasant smell and is covered by non-glandular and glandular trichomes, which give it a velvety look. Glandular trichomes are capitate trichomes, which occur in three types: (a) short capitate, characterized by one stalk cell, two secretory cells and a small subcuticular space; (b) long capitate, characterized by a stalk of two or three cells, four secretory cells and a large subculicular space; (c) very long capitate, characterized by a stalk of three or more cells and four or more secretory cells, each of them bearing a small swelling space on the apex. Trichomes of types (a) and (b) are present over the whole plant-leaves [adaxial side bears only type (a) along the veins], stalk and inflorescences. Type (c) is present only on the inflorescence-flowers, calices and bracts. The plant is used for medicinal purposes (mostly as an antispasmodic) jn Italian folk medicine. The oil composition of inflorescences and leaves of S. sylvatica from ltaly was analysed by GC-MS. The most abundant compounds in the oil from the inflorescences were germacrene D (55.2%), (E)--farnesene (9.1%) and n-tetracosane (6.9%), whilst germacrene D (31.7%), n-tetracosane (7.8%) and mint sulphide (6.4%) were the main compounds in the oil from the leaves. Other compounds: -pinene, -pinene, myrcene, limonene, -3-carene, (E)- -ocimene, -terpinene, terpinolene, linalool, n-undecane, nonanal, safrole, -cubebene, -copaene, -bourbonene, -elemene, dodecanal, -caryophyllene, -copaene, (E)--bergamotene, cis-muurola-3,5-diene, -humulene, allo-aromadendrene, -muurolene, bicyclogermacrene, -muurolene, (E.E)--farnesene, germacrene A, -cadinene, -cadinene, -sesquiphellandrene, (E)--bisabolene, elemol, (E)-nerolidol, germacrene, viridiflorol, -eudesmol, (Z)-cadin-4-en-7-ol, epi--cadinol, epi--muurolol, -bisabolol, -eudesmol acetate, hexadecanoic acid, phytol, octadecanol, n-tricosane

Glandular trichomes as further differential characters between <i>Stachys</i> subgenus <i>Betonica</i> (L.) Bhattacharjee and <i>Stachys</i> subgenus <i>Stachys</i>

<div><p></p><p>The genus <i>Stachys</i> L. has always presented great taxonomic and nomenclatural problems; the identification of two different genera, <i>Betonica</i> and <i>Stachys</i>, or of a single genus, <i>Stachys</i>, with the subgenera <i>Betonica</i> and <i>Stachys</i>, is still debated. In this work, different types of glandular trichomes (peltate and capitate) occurring in species belonging to both subgenera <i>Betonica</i> and <i>Stachys</i> are described. Observations were carried out on living plants growing in Italy, using scanning electron microscopy (SEM), to characterise trichome structure and distribution on vegetative and reproductive organs, and light microscopy (LM) to characterise their type of secretion, by means of histochemical methods. <i>Stachys</i> subgenus <i>Betonica</i> presents only peltate hairs, while <i>Stachys</i> subgenus <i>Stachys</i> has different types of large capitate hairs lacking in the subgenus <i>Betonica</i>. Furthermore, the peltate trichomes of the subgenus <i>Betonica</i> show an unusual secretion composed of flavonoids and essential oils. A thorough examination of numerous exsiccata belonging to subgenera <i>Betonica</i> and <i>Stachys</i>, stored in the Herbarium Centrale Italicum of Florence (FI), confirmed observations made on living material. The recorded characters allowed a clear distinction between the species of the subgenus <i>Betonica</i> and those of the subgenus <i>Stachys</i>. Consequently, a higher taxonomic rank than subgenus should be recommended for these taxa.</p> </div

The role of secreting structures position on the leaf volatile organic compounds of Hypericum androsaemum.

Hypericum androsaemum L. presents typical translucent, essential oil producing glands, which are distributed on the leaf along both margins (margin glands) and on the lamina (lamina glands). The gland secretion was studied by histochemical and chemical analysis; the gland content was sampled directly from the secretory glands, and the volatile organic compounds (VOC) of the margin and lamina glands were separately analyzed. The lipophilic fraction of the lamina glands had as main components: (E)-2-hexenal (15.5%), hexadecanoic acid (14.7%), β-caryophyllene (11.2%), germacrene B (11.0%) and γ-himachalene (9.8%). The lipophilic fraction of the margin glands had as its main components: β-pinene (22.0%), limonene (17.6%), (E)-β-ocimene (6.1%), methyl linoleate (5.7%), terpinolene (5.4 %), (E)-2-hexenal (4.9%) and α-pinene (4.1%)

Composition of essential oils from leaves and flowers of Stachys germanica subsp. salviifolia (Ten.) Gams (Labiatae) and related secretory structures

The essential oils from both leaves (L) and flowers (F) of Stachys germanica subsp. salviifolia (Ten.) Gams (Labiatae/Lamiaceae) from Italy were analyzed by GC-MS for the first time. The distribution, morphology and histochemistry of the different types of glandular trichomes present on the epidermal surface were also determined. Twenty-nine constituents, representing 89.4% of the total leaf oil, and forty-one compounds, forming 97.8% of the total flower oil, were identified. Germacrene D (39.4%), phytol (10.2%), β-bourbonene (3.5%) and β-ylangene (3.3%) were recognized as the main constituents of the leaf essential oil, while limonene (24.1%), β-pinene (18.7%), germacrene D (12.8%) and ( E)-nerolidol (6.6%) were the main compounds of the flower essential oil