Australia's leading public health body delays action on the revision of the public health goal for blood lead exposures.

Globally, childhood blood lead levels have fallen precipitously in developed countries since the 1970s following action by international bodies such as the WHO and Food and Agricultural Organization (FAO) of the United Nations. These reductions have been affected by the activities of national agencies such as the US EPA and US Centers for Disease Control and Prevention in the establishment of air lead and blood lead standards, the introduction of legislation to remove lead from petrol, paint and consumer products and tighter restrictions on lead emissions. The outcome of recent major international reviews of research into the effects of low-level lead exposures (e.g. by WHO, USA health and environmental agencies, German and Canadian health bodies) has resulted in recommendations to reduce and eliminate lead exposures. By contrast, Australian policy responses to the incontrovertible evidence that adverse neurocognitive and behavioural effects that occur at levels well below the current national goal of 10µg/dL have stalled. The delayed response by Australia occurs at a time when blood lead levels in two of Australia's three primary lead mining and smelting cities: Port Pirie, South Australia and Broken Hill, New South Wales, are rising. In the third city, Mount Isa, Queensland, there is still no systematic, annual testing of childhood blood lead values. This is despite the fact that Mount Isa has the highest lead (and other toxic metals such as cadmium and arsenic) emissions to the environment (120tonnes of lead in 2011/12) from any single point source in Australia. It is clear that both state and national policy approaches to the ongoing risks of lead exposure need to be revised urgently and in line with contemporary international standards. Recommended changes should include a new lower blood lead intervention level of no more than 5µg/dL, with a national goal for all children under 5years of age to have a blood lead level of below 1µg/dL by 2020. In order to achieve any new lower exposure goals other relevant lead standards including air, dust, soil and water must also be revised downwards.

Chemical hazards in the organisation.

The use of hazardous chemicals in organisations represents a substantial risk to occupational health, safety and the environment (OHSE). Organisational directors and managers have a responsibility to provide and maintain organisational management systems that manage these risks. The risk management approach of establishing organisational considerations, identifying chemical hazards (health and environmental), assessing and controlling risks and evaluating management activities has become the de facto means of managing organisational hazards in general and may be satisfactorily applied to the management of chemicals in the organisation. The Globally Harmonized System for the Classification and Labelling of Chemicals (GHS) is now at the forefront of major regulatory issues facing the chemicals manufacturing industry and downstream users of chemicals. The GHS offers one system for the classification of all dangerous, toxic and environmental (ecotoxic) effects of chemicals. Organisations should develop occupational health, safety and environment (OHSE) management systems which contain programs and procedures that contain systems for inventory control, hazard communication, competency training, risk assessment and control, transport and storage, monitoring and health surveillance, chemical emergencies (including accident investigation), waste minimisation and disposal, record keeping and management system review.

Purified c-phycoerythrin: safety studies in rats and protective role against permanganate-mediated fibroblast-DNA damage.

We have evaluated in vitro cytotoxicity of cyanobacterial phycoerythrin (C-PE) on three human cell lines by cell proliferation and neutral red uptake assays. No toxic effects of C-PE were observed to any of the cell lines tested. The protective role of purified C-PE to potassium permanganate-mediated human fibroblast-DNA damage was assessed by comet assay at 0 (control), 10 and 20 microg C-PE ml(-1) doses in pre-, simultaneous and post-mutagen exposure conditions. Significant DNA damage was detected only in post-mutagen exposure conditions. Our findings confirmed that the C-PE is non-toxic and provides protection against permanganate-mediated DNA damage. The preliminary acute (2000 mg C-PE kg(-1) body weight, b.w.) and 90 day sub-chronic (0, 5, 15 and 25 mg C-PE kg(-1) b.w./day) oral toxicity studies of purified C-PE in male albino rats showed no mortality or treatment-related major clinical signs, and all the doses of C-PE were well tolerated. The no observed adverse effect level and no observed effect level were found to be 15 and 5 mg C-PE kg(-1) b.w./day respectively.

An integrated in vitro approach for toxicity testing of airborne contaminants.

While it is possible to establish the chemical composition of air pollutants through conventional air sampling and analytical techniques, such data do not provide direct measures of toxicity and the potential mechanisms that induce adverse effects. The aim of this study was to optimize in vitro methods for toxicity testing of airborne contaminants. An integrated approach was designed in which appropriate exposure techniques were developed. A diversified range of in vitro assays using multiple human cell systems were implemented. Direct exposure of cells to airborne contaminants was developed by culturing cells on porous membranes in conjunction with a horizontal diffusion chamber system. Concentration-response curves were generated allowing the measurement of toxicity endpoints. Regression analysis indicated a significant correlation between in vitro and published in vivo toxicity data for the majority of selected chemical contaminants. Airborne IC50 values were calculated for selected volatile organic compounds (xylene, 5350 +/- 328 ppm > toluene, 10,500 +/- 527 ppm) and gaseous contaminants (NO2, 11 +/- 3.54 ppm > SO2, 48 +/- 2.83 ppm and > NH3, 199 +/- 1.41 ppm). Results of this study indicate the significant potential of in vitro methods as an advanced technology for toxicity assessment of airborne contaminants.

The development of the globally harmonized system (GHS) of classification and labelling of hazardous chemicals.

The hazards of chemicals can be classified using classification criteria that are based on physical, chemical and ecotoxicological endpoints. These criteria may be developed be iteratively, based on scientific or regulatory processes. A number of national and international schemes have been developed over the past 50 years, and some, such as the UN Dangerous Goods system or the EC system for hazardous substances, are in widespread use. However, the unnecessarily complicated multiplicity of existing hazard classifications created much unnecessary confusion at the user level, and a recommendation was made at the 1992 Rio Earth summit to develop a globally harmonized chemical hazard classification and compatible labelling system, including material safety data sheets and easily understandable symbols, that could be used for manufacture, transport, use and disposal of chemical substances. This became the globally harmonized system for the Classification and Labelling of Chemicals (GHS). The developmental phase of the GHS is largely complete. Consistent criteria for categorising chemicals according to their toxic, physical, chemical and ecological hazards are now available. Consistent hazard communication tools such as labelling and material safety data sheets are also close to finalisation. The next phase is implementation of the GHS. The Intergovernmental Forum for Chemical Safety recommends that all countries implement the GHS as soon as possible with a view to have the system fully operational by 2008. When the GHS is in place, the world will finally have one system for classification of chemical hazards.

The toxicity of commercial jet oils.

Jet oils are specialized synthetic oils used in high-performance jet engines. They have an appreciable hazard due to toxic ingredients, but are safe in use provided that maintenance personnel follow appropriate safety precautions and the oil stays in the engine. Aircraft engines that leak oil may expose others to the oils through uncontrolled exposure. Airplanes that use engines as a source of bleed air for cabin pressurization may have this source contaminated by the oil if an engine leaks. Examination of the ingredients of the oil indicates that at least two ingredients are hazardous: N-phenyl-1-naphthylamine (a skin sensitizer) and tricresyl phosphate (a neurotoxicant, if ortho-cresyl isomers are present). Publicly available information such as labels and MSDS understates the hazards of such ingredients and in the case of ortho-cresyl phosphates by several orders of magnitude.

Metals in drinking water from new housing estates in the Sydney area.

Metals in drinking water were measured in 95 new houses less than 18 months old in the Sydney metropolitan area. Three samples (first-flush, post-first-flush, and fully flushed water) were collected from each house, and "control" samples from the five Sydney Water points that supplied the houses, a total of 326 samples. They were analyzed for Pb, Cu, Mn, Zn, Cd, and Al. At the supply points, the levels of all metals were at or below Australian Drinking Water Guidelines (ADWG). In the houses, metal levels varied. Of the first-flush samples, Pb was above ADWG in 60% and above US EPA Guidelines in 81%, Cu was above ADWG in 12%, and Cd was above ADWG in 4%. Of the post-first-flush samples, Pb was above ADWG in 24%, Cu was above ADWG in 18%, Cd was above ADWG in 1%, and Zn was above ADWG in 1%. The other metal contaminants (Mn and Al) were within ADWG. In fully flushed water, the levels of all metals were well below ADWG.

Mechanisms of multiple chemical sensitivity.

Sensitivity to chemicals is a toxicological concept, contained in the dose-response relationship. Sensitivity also includes the concept of hypersensitivity, although controversy surrounds the nature of effects from very low exposures. The term multiple chemical sensitivity has been used to describe individuals with a debilitating, multi-organ sensitivity following chemical exposures. Many aspects of this condition extend the nature of sensitivity to low levels of exposure to chemicals, and is a designation with medical, immunological, neuropsychological and toxicological perspectives. The basis of MCS is still to be identified, although a large number of hypersensitivity, immunological, psychological, neurological and toxicological mechanisms have been suggested, including: allergy; autosuggestion; cacosomia; conditioned response; immunological; impairment of biochemical pathways involved in energy production; impairment of neurochemical pathways; illness belief system; limbic kindling; olfactory threshold sensitivity; panic disorder; psychosomatic condition; malingering; neurogenic inflammation; overload of biotransformation pathways (also linked with free radical production); psychological or psychiatric illness; airway reactivity; sensitisation of the neurological system; time dependent sensitisation, toxicant induced loss of tolerance. Most of these theories tend to break down into concepts involving: (1) disruption in immunological/allergy processes; (2) alteration in nervous system function; (3) changes in biochemical or biotransformation capacity; (4) changes in psychological/neurobehavioural function. Research into the possible mechanisms of MCS is far from complete. However, a number of promising avenues of investigation indicate that the possibility of alteration of the sensitivity of nervous system cells (neurogenic inflammation, limbic kindling, cacosomia, neurogenic switching) are a possible mechanism for MCS.

The dermal toxicity of cement.

Cement and concrete are products used widely in the construction sector, with a traditional perception that any hazards that they have are limited to dermatitis in a small number of workers. In some cases, employers and builders do not think that concrete is a chemical. However, contact dermatitis is one of the most frequently reported health problems among construction workers. A review of the available literature suggests that cement has constituents that produce both irritant contact dermatitis and corrosive effects (from alkaline ingredients such as lime) and sensitization, leading to allergic contact dermatitis (from ingredients such as chromium). These findings indicate that cement and concrete should be treated as hazardous materials, and that workers handling such products should reduce exposure wherever possible. Initiatives to reduce the chromium content of cement have been shown to be successful in reducing the incidence of allergic dermatitis, although the irritant form remains.