Rebecca Slack

Occupational cancer burden in Great Britain

A sound knowledge base is required to target resources to reduce workplace exposure to carcinogens. This project aimed to provide an objective estimate of the burden of cancer in Britain due to occupation. This volume presents extensive analyses for all carcinogens and occupational circumstances defined as definite or probable human occupational carcinogens by the International Agency for Research on Cancer. This article outlines the structure of the supplement – two methodological papers (statistical approach and exposure assessment), eight papers presenting the cancer-specific results grouped by broad anatomical site, a paper giving industry sector results and one discussing work-related cancer-prevention strategies. A brief summary of the methods and an overview of the updated overall results are given in this introductory paper. A general discussion of the overall strengths and limitations of the study is also presented. Overall, 8010 (5.3%) total cancer deaths in Britain and 13, 598 cancer registrations were attributable to occupation in 2005 and 2004, respectively. The importance of cancer sites such as mesothelioma, sinonasal, lung, nasopharynx, breast, non-melanoma skin cancer, bladder, oesophagus, soft tissue sarcoma and stomach cancers are highlighted, as are carcinogens such as asbestos, mineral oils, solar radiation, silica, diesel engine exhaust, coal tars and pitches, dioxins, environmental tobacco smoke, radon, tetrachloroethylene, arsenic and strong inorganic mists, as well as occupational circumstances such as shift work and occupation as a painter or welder. The methods developed for this project are being adapted by other countries and extended to include social and economic impact evaluation.

Priority water research questions as determined by UK practitioners and policy makers

Several recent studies have emphasised the need for a more integrated process in which researchers, policy makers and practitioners interact to identify research priorities. This paper discusses such a process with respect to the UK water sector, detailing how questions were developed through inter-disciplinary collaboration using online questionnaires and a stakeholder workshop. The paper details the 94 key questions arising, and provides commentary on their scale and scope. Prioritization voting divided the nine research themes into three categories: (1) extreme events (primarily flooding), valuing freshwater services, and water supply, treatment and distribution [each >150/1109 votes]; (2) freshwater pollution and integrated catchment management [100-150 votes] and; (3) freshwater biodiversity, water industry governance, understanding and managing demand and communicating water research [50-100 votes]. The biggest demand was for research to improve understanding of intervention impacts in the water environment, while a need for improved understanding of basic processes was also clearly expressed, particularly with respect to impacts of pollution and aquatic ecosystems. Questions that addressed aspects of appraisal, particularly incorporation of ecological service values into decision making, were also strongly represented. The findings revealed that sustainability has entered the lexicon of the UK water sector, but much remains to be done to embed the concept operationally, with key sustainability issues such as resilience and interaction with related key sectors, such as energy and agriculture, relatively poorly addressed. However, the exercise also revealed that a necessary condition for sustainable development, effective communication between scientists, practitioners and policy makers, already appears to be relatively well established in the UK water sector.

Human exposure assessment of different arsenic species in household water sources in a high risk arsenic area

Understanding arsenic speciation in water is important for managing the potential health risks associated with chronic arsenic exposure. Most arsenic monitoring studies to date have only measured total arsenic, with few looking at arsenic species. This study assessed 228 ground water sources in six unstudied villages in Pakistan for total, inorganic and organic arsenic species using ion chromatography inductively coupled plasma collision reaction cell mass spectrometry. The concentration levels approached 3090μgL-1 (95% CI, 130.31, 253.06) for total arsenic with a median of 57.55μgL-1, 3430μgL-1 (median=52) for arsenate (As+5) and 100μgL-1 (median=0.37) for arsenite (As+3). Exceedance of the WHO provisional guideline value for arsenic in drinking water (10μgL-1) occurred in 89% of water sources. Arsenic was present mainly as arsenate (As+5). Average daily intake of total arsenic for 398 residents living in the sampled houses was found up to 236.51μgkg-1day-1. This exposure estimate has indicated that 63% of rural residents exceeded the World Health Organizations provisional tolerable daily intake (PTDI) of 2.1μgkg-1day-1 body weight. Average daily intake of As+5 was found to be 15.63μgkg-1day-1 (95% CI, 5.53, 25.73) for children ≤16 and 15.07μgkg-1day-1 (95% CI, 10.33, 18.02) for adults. A mean daily intake of 0.09μgkg-1day-1 was determined for As+3 for children and 0.26μgkg-1day-1 for adults. Organic arsenic species such as monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and Arsenobetaine (AsB) were found to be below their method detection limits (MDLs).

Refinement of arsenic attributable health risks in rural Pakistan using population specific dietary intake values

BACKGROUND Previous risk assessment studies have often utilised generic consumption or intake values when evaluating ingestion exposure pathways. If these values do not accurately reflect the country or scenario in question, the resulting risk assessment will not provide a meaningful representation of cancer risks in that particular country/scenario. OBJECTIVES This study sought to determine water and food intake parameters for one region in South Asia, rural Pakistan, and assess the role population specific intake parameters play in cancer risk assessment. METHODS A questionnaire was developed to collect data on sociodemographic features and 24-h water and food consumption patterns from a rural community. The impact of dietary differences on cancer susceptibility linked to arsenic exposure was evaluated by calculating cancer risks using the data collected in the current study against standard water and food intake levels for the USA, Europe and Asia. A probabilistic cancer risk was performed for each set of intake values of this study. RESULTS Average daily total water intake based on drinking direct plain water and indirect water from food and beverages was found to be 3.5Lday-1 (95% CI: 3.38, 3.57) exceeding the US Environmental Protection Agencys default (2.5Lday-1) and World Health Organizations recommended intake value (2Lday-1). Average daily rice intake (469gday-1) was found to be lower than in India and Bangladesh whereas wheat intake (402gday-1) was higher than intake reported for USA, Europe and Asian sub-regions. Consequently, arsenic-associated cumulative cancer risks determined for daily water intake was found to be 17 chances in children of 3-6years (95% CI: 0.0014, 0.0017), 14 in children of age 6-16years (95% CI: 0.001, 0.0011) and 6 in adults of 16-67years (95% CI: 0.0006, 0.0006) in a population size of 10,000. This is higher than the risks estimated using the US Environmental Protection Agency and World Health Organizations default recommended water intake levels. Rice intake data showed early life cumulative cancer risks of 15 chances in 10,000 for children of 3-6years (95% CI: 0.0012, 0.0015), 14 in children of 6-16years (95% CI: 0.0011, 0.0014) and later life risk of 8 adults (95% CI: 0.0008, 0.0008) in a population of 10,000. This is lower than the cancer risks in countries with higher rice intake and elevated arsenic levels (Bangladesh and India). Cumulative cancer risk from arsenic exposure showed the relative risk contribution from total water to be 51%, from rice to be 44% and 5% from wheat intake. CONCLUSIONS The study demonstrates the need to use population specific dietary information for risk assessment and risk management studies. Probabilistic risk assessment concluded the importance of dietary intake in estimating cancer risk, along with arsenic concentrations in water or food and age of exposed rural population.

Human Health Risk Assessment For Arsenic: A Critical Review

ABSTRACT Millions of people are exposed to arsenic resulting in a range of health implications. This paper provides an up-to-date review of the different sources of arsenic (water, soil, and food), indicators of human exposure (biomarker assessment of hair, nail, urine, and blood), epidemiological and toxicological studies on carcinogenic and noncarcinogenic health outcomes, and risk assessment approaches. The review demonstrates a need for more work evaluating the risks of different arsenic species such as, arsenate, arsenite monomethylarsonic acid, monomethylarsonous acid, dimethylarsinic acid, and dimethylarsinous acid as well as a need to better integrate the different exposure sources in risk assessments.

Chemicals in Waste: Household Hazardous Waste

Publisher Summary Household hazardous waste (HHW) is a term used to describe hazardous wastes entering the municipal waste stream. It represents a variety of waste types classified together based on the possession of hazardous properties. This chapter takes a look at the problems related to the disposal of chemicals and other hazardous substances used in the home. HHW is a small proportion of the municipal waste stream, but the potential risks to the environment and health are disproportionate to its size. Although estimates of the amount of HHW vary from region to region and across national boundaries, it generally comprises 1–4% of municipal solid waste (MSW). Internationally, most HHW is co-disposed with MSW to municipal waste landfills. Co-disposal of potentially hazardous wastes can lead to an increase in hazard status; not only are these substances potentially dangerous to the environment and health, but they can also induce changes in other waste streams by reacting directly with the waste or by altering the redox environment. Landfill simulations, based on current MSW disposal patterns, reveal the risk to the environment from leakage of potentially hazardous materials from landfills to be small but existent. There is a growing tendency for waste disposal authorities to make provision for the separate collection of many items of HHW. The increased cost of separate HHW collection and disposal must be considered alongside the new environmental and health risks posed by changes to disposal practice and the general trend of reduced hazardous content of most consumer goods.

Evaluating water quality and ecotoxicology assessment techniques using data from a lead and zinc effected upland limestone catchment

Point and diffuse sources associated with historical metal ore mining are major causes of metal pollution. The understanding of metal behaviour and fate has been improved by the integration of water chemistry, metal availability and toxicity. Efforts have been devoted to the development of efficient methods of assessing and managing the risk posed by metals to aquatic life and meeting national water quality standards. This study focuses on the evaluation of current water quality and ecotoxicology techniques for the metal assessment of an upland limestone catchment located within a historical metal (lead ore) mining area in northern England. Within this catchment, metal toxicity occurs at circumneutral pH (6.2-7.5). Environmental Quality Standards (EQSs) based on a simple single concentration approach like hardness based EQS (EQS-H) are more overprotective, and from sixteen sites monitored in this study more than twelve sites (>75%) failed the EQSs for Zn and Pb. By increasing the complexity of assessment tools (e.g. bioavailability-based (EQS-B) and WHAM-FTOX), less conservative limits were provided, decreasing the number of sites with predicted ecological risk to seven (44%). Thus, this research supports the use of bioavailability-based approaches and their applicability for future metal risk assessments.

Arsenic species in wheat, raw and cooked rice: Exposure and associated health implications

Arsenic concentrations above 10μgL-1 were previously found in 89% of ground water sources in six villages of Pakistan. The present study has ascertained the health risks associated with exposure to total arsenic (tAs) and its species in most frequently consumed foods. Inorganic arsenic (iAs) concentrations were found to be 92.5±41.88μgkg-1, 79.21±76.42μgkg-1, and 116.38±51.38μgkg-1 for raw rice, cooked rice and wheat respectively. The mean tAs concentrations were 47.47±30.72μgkg-1, 71.65±74.7μgkg-1, 105±61.47μgkg-1. Wheat is therefore demonstrated to be a significant source of arsenic exposure. Dimethylarsinic acid was the main organic species detected in rice, whilst monomethylarsonic acid was only found at trace levels. Total daily intake of iAs exceeded the provisional tolerable daily intake of 2.1μgkg-1day-1 body weight in 74% of study participants due to concurrent intake from water (94%), wheat (5%) and raw rice (1%). A significant association between tAs in cooked rice and cooking water resulted in tAs intake 43% higher in cooked rice compared to raw rice. The study suggests that arsenic intake from food, particularly from wheat consumption, holds particular significance where iAs is relatively low in water. Chronic health risks were found to be significantly higher from wheat intake than rice, whilst the risk in terms of acute effects was below the USEPAs limit of 1.0. Children were at significantly higher health risk than adults due to iAs exposure from rice and/or wheat. The dietary exposure of participants to tAs was attributable to staple food intake with ground water iAs <10μgL-1, however the preliminary advisory level (200μgkg-1) was achievable with rice consumption of ≤200gday-1 and compliance with ≤10μgL-1 iAs in drinking water. Although the daily iAs intake from food was lower than total water intake, the potential health risk from exposure to arsenic and its species still exists and requires exposure control measures.

The effect of association between inefficient arsenic methylation capacity and demographic characteristics on the risk of skin lesions

&NA; This study was conducted in rural Pakistan to assess the dose‐response relationship between skin lesions and arsenic exposure and their variation by demographic characteristics. The study included 398 participants (66 participants with skin lesions and 332 without) residing in six previously unstudied villages exposed to ground water arsenic in the range of < 1 to 3090 &mgr;g L− 1. The skin lesions identification process involved interview and physical examinations of participants followed by confirmation by a physician according to UNICEF criteria. Urinary inorganic arsenic (iAs), total arsenic (tAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were analysed to determine methylation capacity, methylation efficiency and the dose‐response relationship with skin lesions. Study participants with skin lesions were found to be exposed to arsenic > 10 &mgr;g L− 1 with a daily arsenic intake of 3.23 ± 3.75 mg day− 1 from household ground water sources for an exposure duration of 10–20 years. The participants with skin lesions compared to those without skin lesions showed higher levels of urinary iAs (133.40 ± 242.48 vs. 44.24 ± 86.48 &mgr;g g− 1 Cr), MMA (106.38 ± 135.04 vs. 35.43 ± 39.97 &mgr;g g− 1 Cr), MMA% (15.26 ± 6.31 vs.12.11 ± 4.68) and lower levels of DMA% (66.99 ± 13.59 vs. 73.39 ± 10.44) and secondary methylation index (SMI) (0.81 ± 0.11 vs. 0.86 ± 0.07). Study participants carrying a lower methylation capacity characterized by higher MMA% (OR 5.06, 95% CI: 2.09–12.27), lower DMA% (OR 0.64, 95% CI: 0.33–1.26), primary methylation index (PMI) (OR 0.56, 95% CI: 0.28–1.12) and SMI (OR 0.43, 95% CI: 0.21–0.88) had a significantly higher risk of skin lesions compared to their corresponding references after adjusting for occupation categories. The findings confirmed that inefficient arsenic methylation capacity was significantly associated with increased skin lesion risks and the effect might be modified by labour intensive occupations. HighlightsPositive association of arsenic exposure and skin lesions with labour occupations.Significant dose response relationship between arsenic exposure and skin lesions.Inefficient arsenic methylation capacity significantly associated with skin leisons.Variability in 20 houses, 28 persons with and 25 persons without skin problems.

Assessment of arsenic species in human hair, toenail and urine and their association with water and staple food

Arsenic intake from household drinking/cooking water and food may represent a significant exposure pathway to induce cancer and non-cancer health effects. This study is based on the human biomonitoring of 395 volunteers from 223 households with private water sources located in rural Punjab, Pakistan. This work has shown the relative contribution of water and staple food to arsenic intake and accumulation by multiple biological matrix measurements of inorganic and organic arsenic species, while accounting for potential confounders such as age, gender, occupation, and exposure duration of the study population. Multi-variable linear regression showed a strong significant relationship between total arsenic (tAs) intake from water and concentrations of tAs, inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) in urine and toenail samples. tAs intake from staple food (rice and wheat) also showed a strong significant relationship with hair tAs and iAs. The sole impact of staple food intake on biomarkers was assessed and a significant correlation was found with all of the urinary arsenic metabolites. Toenail was found to be the most valuable biomarker of past exposure to inorganic and organic arsenic species of dietary and metabolic origin.