Effectiveness of interventions for preventing injuries in the construction industry: results of an updated Cochrane systematic review

Various interventions to prevent occupational injuries in the construction industry have been proposed and studied. This continuing updated Cochrane review systematically summarizes the most current scientific evidence on the effectiveness of interventions to prevent injuries associated with construction work. Search terms that covered the concepts of ‘construction workers’, ‘injury’, ’safety’ and ‘study design’ were used to identify intervention studies in five electronic databases up to April 2017. Acceptable study designs included randomized controlled trials (RCT), controlled before–after studies (CBA) and interrupted time series (ITS). In total 17 studies, 14 ITS and three CBA studies, from the US (6), UK (2), Italy (3), Denmark (1), Finland (1), Austria (1) Germany (1) Spain (1), Belgium (1) met the inclusion criteria. Most studies were at high risk of bias. There is very low-quality evidence that introducing regulations as such may or may not result in a decrease in fatal and non-fatal injuries. There is also very low-quality evidence that regionally oriented safety campaigns, training, inspections or the introduction of occupational health services may not reduce non-fatal injuries in construction companies. There is very low-quality evidence that company-oriented safety interventions such as a multifaceted safety campaign, a multifaceted drug workplace programme and subsidies for replacement of scaffoldings may reduce non-fatal injuries among construction workers

Interventions to prevent injuries in construction workers

Background Construction workers are frequently exposed to various types of injury-inducing hazards. A number of injury prevention interventions have been proposed, yet their effectiveness is uncertain. Objectives To assess the effects of interventions to prevent injuries in construction workers. Search methods We searched the Cochrane Injuries Group’s specialised register, CENTRAL,MEDLINE, EMBASE, PsycINFO,OSH-ROM(including NIOSHTIC and HSELINE), Scopus, Web of Science and EI Compendex to September 2011. The searches were not restricted by language or publication status. The reference lists of relevant papers and reviews were also searched. Selection criteria Randomised controlled trials, controlled before-after (CBA) studies and interrupted time series (ITS) of all types of interventions for preventing fatal and non-fatal injuries among workers at construction sites. Data collection and analysis Two review authors independently selected studies, extracted data and assessed study quality. For ITS, we re-analysed the studies and used an initial effect, measured as the change in injury-rate in the year after the intervention, as well as a sustained effect, measured as the change in time trend before and after the intervention

Mineral investigations in the Ben Nevis and Ballachulish areas of the Scottish Highlands

Molybdenite in the Ben Nevis igneous complex was observed by Haslam (1965) and placed on record by Gallagher and others (1971). The purpose of the present investigation was to examine the distribution and mode of occurrence of the mineralisation and assess its significance

Disseminated copper-molybdenum mineralisation near Ballachulish, Highland Region

Chalcopyrite-pyrite-molybdenite mineralisation, in disseminated, veinlet and fracture-filling forms, is developed in adamellite and microadamellite in the Ballachulish igneous complex. Minor scheelite is associated with the sulphides, but is mostly confined to the adamellite. The mineralisation occurs sporadically over an area of at least 1800 x 800 m. It is best developed in and around the eastern part of the microadamellite over an area of about 250 x 450 m, where it was observed over a.vertical interval of 250 m from the highest exposure to the base of a borehole. An IP survey showed that chargeability values are slightly higher in this area. The grade is variable. In 10 ft (3 m) lengths of core, the maximum Cu content was 264 ppm and the maximum molybdenum content 501 ppm, but the average tenor over the (250 x 450 m) mineralised area is not more than 50-100 ppm Cu and lo-30 ppm MO. Selected mineralised outcrop samples gave values of up to 2386 ppm Cu, 9257 ppm MO, 2434 ppm W, 0.31 ppm Au and 8 ppm Ag. Rb-Sr isotopic studies indicate that the ore minerals were deposited shortly after emplacement of the host rocks, and it is considered that they were introduced by a hydrothermal system which, compared with those of classic porphyry models, was small in extent and weak in intensity. Sericitic alteration is generally associated with the mineralisation, but there is no potassic alteration evident and the standard zonation of porphyry copper deposits is absent. There is very little K or Rb metasomatism, the best defined chemical change being a loss of Sr in altered rocks. The hydrothermal fluids, as seen in fluid inclusions, were of moderate salinity, unlike the high salinity fluids usually characteristic of porphyry copper deposits. Anomalously low Rb and high K/Rb values in the unaltered microadamellite are attributed to the separation of a Rb-rich aqueous fluid from the microadamellite before or at the time of consolidation of the rock. The mineralised area lies adjacent to and northwest of a NNE-trending shatter belt, which may have provided structural control at depth, although at the present level of exposure the microadamellite body appears to be the structural control

Disseminated molybdenum mineralisation in the Etive plutonic complex in the western Highlands of Scotland

Molybdenite, mainly in quarts veinlets, ocours over an area about 5 km in diameter within the Central Starav Granite. Although selected samples of mineralised rock have been shown to contain up to 0.9% MO, incidence of sulphide mineral is too sparse, even in the best areas, for a meaningful estimate of tenor to be given. Molybdenite is usually accompanied by pyrite. Chalcopyrite and scheelite are also widespread, though less common. Mild hydrothermal alteration accompanies the mineralisation, but there is no pervasive or zoned alteration, nor is there any K or Rb metasomatism. It is suggested that the ore minerals were deposited from hydrothermal fluids which, for lack of any structural or physico-chemical constraints, circulated freely throughout a large volume of rock with the consequence that the ore minerals are widely dispersed. Within the central mineralised area, the Central Starav Granite is more evolved in composition below 650 m than above that altitude, suggesting that present exposure may be near the original roof of the intrusion. Most of the molybdenite mineralisation lies below 650 m and the Co2 contents of fluid inclusions are generally higher at higher altitudes. A drainage geochemical survey, covering most of the Etive plutonic complex, involved the collection and chemical analysis of 428 stream sediments and panned concentrates. The highest concentrations of MO in stream sediment (40 - 120 ppm) came from streams draining the central mineralised area and only this area was examined in detail. The investigation provided no evidence for the existence of exploitable mineral deposits at surface or for their prediction in depth. The possible extent of the mineralised body at depth can only be tested by drilling, but it is suggested that further examination of exposures, collection of additional samples of vein quarts for fluid inclusion studies, and an Induced Polarisation survey would provide more information about mineralisation at and near the surface and might help to define a target for drilling

Miscellaneous investigations on mineralisation in sedimentary rocks

Five areas on the outcrop of the Helsby Sandstone Formation (formerly Keuper Sandstone) and Tarporle y Siltstone (formerly Waterstone) (Warrington and others, 1980) coinciding with known mineralisation were selected as targets for a geochemical investigation. About 3750 soil samples were collected and analysed for copper, lead, cobalt and nickel. Geochemical maps are presented to show the occurrence and distribution of anomalous values. In all the five areas investigated the geochemistry of the soils identified the known areas of mineralisation. In several instances other small areas were also indicated where the soil values are anomalously high and are presumed to reflect local, hitherto unknown, mineralisation. None of these areas, however, appear to have the area1 extent necessary for economic deposits. The results of this preliminary investigation indicate that in all cases the mineralisation is very closely associated with permeable and porous sandstone units which are faulted against less permeable units forming trap structlzres for migrating mineralising fluids

A geochemical drainage survey of the Preseli Hills, south-west Dyfed, Wales

A geochemical drainage survey at a density of 1 sample per km2 was carried out across the Preseli Hills, southwest Dyfed. Stream sediment, water and panned concentrate samples were collected from each of 358 sites, and Cu, Pb, Zn, Ba, Fe, Mn, Co, Ni, V, Cr, B, Zr, As, MO and Sn were determined in sediment, Cu, Pb, Zn, Ba, Fe, Mn, Ti, Ni, Sn, As, Ca, Ce, Sr, Sb, Zr, U and MO in panned concentrate and Cu and Zn in water. From a study of regional variation patterns and multivariate statistical analysis, the main sources of geochemical variation in the data were found to be bedrock lithology, mineralisation, contamination and hydromorphic processes. Strong geochemical signatures were shown by dolerite intrusions and by acid volcanics of the Fishguard Volcanic Group. Dark mudstones of the D. murchisoni Beds and Sealyham Volcanic Series also showed characteristic geochemical features whose impact was limited by their restricted and sinuous outcrops. A feature of most of the area is the presence of monazite nodules, generating high levels of rare earth elements and uranium in the panned concentrates. These are particularly high over the Llandeilo-Ashgill sedimentary rocks. Geological thresholds were established using cumulative frequency plots and percentile division. Anomalies due to contamination could be discriminated satisfactorily from those arising from mineralisation only by field observation and mineralogical examination of panned concentrates. In major streams crossing lowland areas and in the vicinity of roads, widespread contamination proved to be the source of most large base metal anomalies. Anomalies related to known mineralisation are located in the southeast of the area, around Llanfyrnach in the Taf valley. Anomalies reflecting hitherto unrecorded bedrock mineralisation may be present in the following areas: a1 b) cl d) Llanfyrnach; anomalies for Cu, Pb, Zn and Ba are more extensive than can be accounted for by the known vein mineralisation. High levels of other elements suggest an association with shales. Crosswell-Crymmych; barium and base metal anomalies are associated with the Fishguard Volcanic Group and overlying pyritiferous dark mudstones of the D. murchisoni Beds. The geological setting of these rocks, deposited in a sulphurous environment on the flanks of an acid volcanic pile, suggests that massive sulphide deposits are a possible target here. Locally, weak arsenic anomalies, old trials and ancient mining records suggest that there is also some potential for Au mineralisation associated with pyrite in veins and mudstones. Minas Dinas and Pentre Ifan; small amounts of gold and chalcopyrite were found in panned concentrates. Very small amounts of cassiterite were found in panned concentrates from several localities, but no source was readily identifiable. The anomalies in the Llanfyrnach and Crosswell areas were considered to. merit more de tailed are the subject of further work by BGS. investigatio

A geochemical survey of part of the Cheviot Hills and investigations of drainage anomalies in the Kingsseat area

The results of a reconnaissance geochemical drainage Introduction survey across an area of 850 km2 in the Cheviot Hills are reported. At each of the 708 sample sites, the - 0.15 mm fraction of the stream sediment, a panned heavy mineral concentrate derived from the - 2 mm fraction of the stream sediment and a water sample were collected. Be, B, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Zr, MO, Sn, Ba, Ph and Lo1 were determined in stream sediment samples; Ti, Mn, Fe, Ni, Cu, Zn, As, Sr, Zr, MO, Sn, Sb, Ba, Ce, Pb, Bi and U in panned concentrate samples and Cu, Zn and Pb in water samples. The survey area is composed largely of andesitic volcanic rocks of Lower Devonian age. Underlying _ Silurian greywackes and shales and overlying Devonian and Carboniferous sedimentary rocks and basaltic lavas are exposed around the periphery of the volcanic complex. The Cheviot granite crops out on the eastern margin of the area. Anomalous concentrations of metals recorded in the drainage samples are, in general, related to (i) known mineral occurrences, (ii) hydrous oxide precipitation and scavenging processes, (iii) the relatively _ widespread occurrence of baryte, (iv) contamination, (v) tourmalinisation and other hydrothermal activity and (vi) high background levels in unmineralised rocks. At several localities, however, the source of an anomaly is uncertain and some of these may reflect hitherto unknbwn mineralisation. Anomaly groupings and regional variation patterns in the data are influenced by major structures such as the Gyle-Harthope fracture zone. Follow-up investigations into a wide range of metal anomalies in the the Kingsseat area involved more detailed drainage sampling, geological mapping at 1: 10 000 scale and petrographic, mineralogical and lithogeochemical studies. Rocks, previously mapped as extrusive mica felsites, are reinterpreted as a high level intrusion complex, named the Cock Law Complex, which contains live distinct types of porphyry. Many of the intrusive and extrusive rocks are highly altered and seven alteration assemblages are identified, arising from sericitisation, kaolinisation, silicification, tourmalinisation, haematisation and carbonate alterations. All except haematisation are related to Lower Devonian igneous activity. Metal enrichments were recorded in many of the analysed rocks. The greatest enrichments, for the widest range of elements, occur in samples taken from a gossanous structure, where the mineralisation has features in common with the epithermal precious-metal style of mineralisation associated with sub-aerial volcanism

Copper-bearing intrusive rocks at Cairngarroch Bay, south-west Scotland

Two intrusion complexes, the Bay and the Glen, probably representing an early phase of the Devonian magmatic episode, and a number of dykes, are emplaced within a folded succession of Silurian sedimentary rocks at Caimgarroch Bay. Only the roof of the Bay Complex, which consists of microtonalite and granodiorite, is exposed. The Glen Complex, of uncertain form, comprises quartz porphyry, porphyritic quartzmicrodiorite and quartz-microdiorite. Exposure is good along the shore line, but much of the area is covered in thick, dmmlinised drift. Local high chargeability zones were identified along three geophysical traverse lines. Soil samples were collected on a 50 m grid over the area of IP anomalies. In addition, water, base of slope talus, and rock samples were chemically analysed Both the intrusion complexes and some of the sedimentary rocks show locally intense hydrothermal alteration. In the Bay Complex narrow zones of bleached rock are rich in calcite, chlorite and pyrite and contain minor chalcopyrite and pyzrhotite. The Glen Complex displays network fracturing, brecciation and locally intense alteration to sericite or calcite. There is locally abundant pyrite in veins and disseminated and rare chalcopyrite. Arsenopyrite is present in wall rock adjacent to the Bay Complex. Rock geochemistry indicates a pervasive but patchy Cu-Fe-As-MO mineralisation in all rock types, with copper enrichment greatest in the Bay Complex where the highest level recorded is over 600 ppm Cu. The mineralisation is accompanied by irregular barium, potassium and strontium enrichment. The K/Rb ratios suggest that the hydrothermal liquors were not entirely late magmatic. The mineralisation and alteration have some characteristics of a porphyry system and it is conceivable that copper enrichment might increase with depth