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MELIACEAE(Mahogany family)
1400 species in 50 genera are found in warm regions. The seeds of several species provide oils. Aglaia odorata (mock lime) is used to provide a scent for clothing and tea (Corner 1952, Arctander 1960). [Summary yet to be added]
25 species are native to Indo Malaysia. The wood of some species can produce respiratory symptoms (Orsler 1973) and skin irritation (von Reis Altschul 1973).
Referring to Melia indica, Corner (1952) notes that the twigs and leaves when broken have a slightly foetid smell of garlic. He notes also that the leaves have insect-repellant properties. The oil obtained from the seeds is known as margosa oil. In Indian traditional medicine, this oil may be used as a dressing for foul ulcers. It is a favourite application for leprosy, urticaria, eczema, ringworm, and scabies. The dry seeds possess the same properties as the oil when bruised, mixed with water and applied to itch. The leaves also are used, after heating over boiling water, as a paste or poultice in skin diseases, boils and ulcers (Nadkarni 1976). Patch tests carried out using the leaves of this species crushed in a small quantity of normal saline elicited no positive reactions in 3 contact dermatitis patients tested in New Delhi, India (Singh et al. 1978). This species was listed as a source of dermatitis by Senear (1933). The sawdust was used as a rubefacient and can produce dermatitis (Irvine 1961). Eight species are found in tropical America (Mabberley 1987). Some yield valuable timber, for example stinking mahogany or citron. Cedrela odorata L., used for cigar boxes, is known as West Indian cedar. Old World species formerly placed in this genus have been referred to Toona M.Roem. The wood dust of some species can produce dermatitis (Hanslian and Kadlec 1966).
Furniture workers who worked with the wood of red bean for 4–5 days developed influenza-like symptoms, vomiting and nose bleeds. The sawdust may also cause severe eczema. The more seasoned the wood, the more virulent it became (Maiden 1909b). A later report of the same problem by Aldersley (1925) referred to the tree erroneously as Castaneospermum australe [sic], a leguminous tree (Cleland 1925). When preparing a quantity of the sawdust for an investigation of its irritant properties, Bisset (1949) noted that shortly after inhaling a quantity of the sawdust, inflammation of the eyes, irritation of the throat and a running nose developed. The irritation of the throat rapidly extended to the lungs and the breathing subsequently became painful and difficult. These symptoms were accompanied by the development of a severe headache and loss of appetite. The following day bleeding from the nose commenced and was followed by severe fits of coughing and bringing-up of blood-spotted phlegm. The mucous membrane of the nose was still irritated after 4 days. This species was said to cause eczema and irritation of the eye and throat (Maiden 1909b). Stavewood is a common name for a tree of this genus which is said to irritate the skin (Thiebault 1965). The charred powdered roots cause violent sneezing (Irvine 1961). 35 species found in tropical and South Africa. Some are known in the lumber trade as cedar or mahogany. A few cases of dermatitis from the wood of this species have been observed in the furniture industry (Wilkinson 1972). Oleffe et al. (1975a) listed tiama as a cause of dermatitis in the Belgian timber industry. The wood may irritate the skin and mucous membranes (Hublet et al. 1972, Oleffe et al. 1975a). Brezina (1921) described a scarlatina-like eruption on the arms which followed polishing "sapeli-mahogany". No patch tests were recorded and the botanical identity of the wood was not certain. Woods and Calnan (1976) reported two cases of dermatitis from the wood dust. A machinist had dermatitis and swelling of the eyelids. The dermatitis spread to face, neck, scalp, elbow flexures, groins, popliteal skin and feet. Another patient was also contact sensitive to Dalbergia. They commented that the wood is extensively used and the incidence of "toxic" effects probably low. Oleffe et al. (1975a) listed this species as a cause of dermatitis in the Belgian timber industry. All the men in contact with this West African wood in a factory complained of severe irritation of the nose and throat (MacKenna and Horner 1954). Orsler (1973) received trade reports of skin and nasal irritation from the wood. Other species known as obobo and Nigerian pear wood, notably Guarea thompsonii have been implicated (Hausen 1970) but the chemicals responsible are unknown. The wood is said to be more irritating than that of G. cedrata (Farmer 1972). The bark of this American tree and other Guarea species smells of musk and, when powdered, has emetic and haemostatic properties (Record & Hess 1943).
The species are difficult to distinguish, especially after felling. They are often imported mixed though Khaya ivorensis has provided the bulk of the timber (Rendle 1956). The wood can produce dermatitis in wood-workers (Morgan and Wilkinson 1965, Morgan and Orsler 1967, Wilkinson 1968, 1970, Morgan et al. 1968). Contact dermatitis from the wood-dust can resemble seborrhoeic dermatitis or neurodermatitis. The dermatitis affected the face, neck and ears but the postauricular skin was spared and the bald rather than the hairy area of the scalp was affected in workmen who did not wear caps. The hands usually escaped (Wilkinson 1973). The outer heart-wood freshly prepared as wood dust in a concentration 10% in petrolatum was satisfactory for patch-testing. Khaya wood dust was not irritant by patch test in contrast to teak (Tectona grandis L.f., fam. Labiatae). Khaya is not a strong sensitiser; 10% of exposed workers were affected and the dermatitis was not severe. A sensitising component of the wood is anthothecol which can be tested at a concentration 0.5% or 0.1% in petrolatum. Higher concentrations carry a risk of active sensitisation. The wood dust does not appear to affect the respiratory tract. Other woods, introduced into shipments of Khaya anthotheca can be distinguished by chemical tests. Several may also produce sensitisation but some are inactive. West African mahogany is a name given to a variety of hardwoods and patch tests should be carried out with botanically identified woods in addition to samples supplied from the work area. In respiratory disease from Khaya, fungus growth in the wood was suspected (Dantin-Gallego et al. 1952). Zafiropoulo et al. (1968) and Hausen (1970) describe dermatitis from the species. Bevan et al. (1963) discuss the chemistry. Khaya anthotheca cross-reacts with Khaya euryphylla but not with Khaya ivorensis. An American report of asthma from mahogany (Sosman et al. 1969) may refer to a Khaya sp. or to a Swietenia sp. "Mahogany from Congo and Ghana" that caused dermatitis in 15 of 68 furniture makers (Shevlyakov 1969) seems to have been a Khaya sp. rather than a Swietenia sp. This species was included in a list of toxic timbers by Czimatis and Hagemann (1910). Some species notably Lovoa klaineana (African walnut) and Lovoa trichiliodes can cause dermatitis, respiratory symptoms and possibly systemic effects in woodworkers (Zafiropoulo et al. 1968, Schweisheimer 1952, Ordman 1949, Allemany-Vall 1958, Symanski 1957). One man who had dermatitis showed positive patch test reactions to L. klaineana and to Mansonia sp. (Woods and Calnan 1976). Eating the fruits causes stomatitis (Verdcourt and Trump 1969, Morton 1971) and the oil from the fruits is irritant (Simpson and Lim 1935). The fruit contains a single large green seed that smells like garlic (Allium sativum L., fam. Alliaceae) when bruised or cut (Corner 1952). MacKenna and Horner (1954) described sneezing, epistaxis, tightness of the chest, body-aches, "marked mental dimness" and bradycardia which affected four men sawing the wood and to a lesser degree other men nearby and the investigating physician. There was no dermatitis. The heart-wood contains a triterpene, katonic acid (King and Morgan 1960). Willis (1973) noted that 7–8 species had been described from tropical America and the West Indies but Styles (1981) recognises only three species and regards these as poorly defined biologically. This genus is the source of valuable timber known as mahogany, much exploited for cabinet work since the 18th century, and formerly used for ship building (Mabberley 1987). The term mahogany has been applied to many timbers from botanically unrelated sources. According to Burkill (1935), more than 60 species have been offered as mahogany. Lamb (1963) concludes that the name mahogany can justifiably refer only to Swietenia and Khaya A.Juss. species, the latter being African in origin.
American mahogany used for cabinet work has become scarcer and largely replaced by Khaya. Some authors have not distinguished between these sources of mahogany (Hausen 1970). Dermatitis from the wood was reported by Herxheimer (1912). Schwartz and Russell (1941) and Steiner and Schwartz (1944) reported dermatitis from use of the woods in boat and airplane manufacture. The chemicals responsible are unknown (Hausen 1970). "Mahogany from Congo and Ghana" which caused dermatitis in 15 of 68 furniture makers (Shevlyakov 1969) seems to have been Khaya sp. rather than Swietenia sp. It has been suggested that Swietenia humilis is merely an ecotype of Swietenia macrophylla; and some consider Swietenia to be monotypic (Helgason et al. 1996).
Orsler (1973) received trade reports of skin irritation from the wood of these and other Toona species. The wood has produced dermatitis and asthma in wood-workers (Hausen 1970, Calnan 1970, Zafiropoulo et al. 1968, Kerharo and Bouquet cited by Irvine 1961, Hublet et al. 1972, Oleffe et al. 1975a). The sawdust is said to make wood cutters spit blood (Irvine 1961). References
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