Dana Hashim

Occupational and environmental exposures and cancers in developing countries.

BACKGROUND Over the past few decades, there has been a decline in cancers attributable to environmental and occupational carcinogens of asbestos, arsenic, and indoor and outdoor air pollution in high-income countries. For low- to middle-income countries (LMICs), however, these exposures are likely to increase as industrialization expands and populations grow. OBJECTIVE The aim of this study was to review the evidence on the cancer risks and burdens of selected environmental and occupational exposures in less-developed economies. FINDINGS A causal association has been established between asbestos exposure and mesothelioma and lung cancer. For arsenic exposure, there is strong evidence of bladder, skin, lung, liver, and kidney cancer effects. Women are at the highest risk for lung cancer due to indoor air pollution exposure; however, the carcinogenic effect on the risk for cancer in children has not been studied in these countries. Cancer risks associated with ambient air pollution remain the least studied in LMICs, although reported exposures are higher than World Health Organization, European, and US standards. Although some associations between lung cancer and ambient air pollutants have been reported, studies in LMICs are weak or subject to exposure misclassification. For pulmonary cancers, tobacco smoking and respiratory diseases have a positive synergistic effect on cancer risks. CONCLUSIONS A precise quantification of the burden of human cancer attributable to environmental and occupational exposures in LMICs is uncertain. Although the prevalence of carcinogenic exposures has been reported to be high in many such countries, the effects of the exposures have not been studied due to varying country-specific limitations, some of which include lack of resources and government support.

Metal contamination of home garden soils and cultivated vegetables in the province of Brescia, Italy: Implications for human exposure.

BACKGROUND For the past century, ferroalloy industries in Brescia province, Italy produced particulate emissions enriched in manganese (Mn), lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), iron (Fe), and aluminum (Al). This study assessed metal concentrations in soil and vegetables of regions with varying ferroalloy industrial activity levels. METHODS Home gardens (n=63) were selected in three regions of varying ferroalloy plant activity durations in Brescia province. Total soil metal concentration and extractability were measured by X-Ray Fluorescence (XRF), aqua regia extraction, and modified Community Bureau of Reference (BCR) sequential extraction. Unwashed and washed spinach and turnips cultivated in the same gardens were analyzed for metal concentrations by flame atomic absorption spectrometry. RESULTS Median soil Al, Cd, Fe, Mn, Pb, and Zn concentrations were significantly higher in home gardens near ferroalloy plants compared to reference home gardens. The BCR method yielded the most mobile soil fraction (the sum of extractable metals in Fractions 1 and 2) and all metal concentrations were higher in ferroalloy plant areas. Unwashed spinach showed higher metal concentrations compared to washed spinach. However, some metals in washed spinach were higher in the reference area likely due to history of agricultural product use. Over 60% of spinach samples exceeded the 2- to 4-fold Commission of European Communities and Codex Alimentarius Commission maximum Pb concentrations, and 10% of the same spinach samples exceeded 2- to 3-fold maximum Cd concentrations set by both organizations. Turnip metal concentrations were below maximum standard reference values. CONCLUSIONS Prolonged industrial emissions increase median metal concentrations and most soluble fractions (BCR F1+F2) in home garden soils near ferroalloy plants. Areas near ferroalloy plant sites had spinach Cd and Pb metal concentrations several-fold above maximum standard references. We recommend thorough washing of vegetables to minimize metal exposure.

The role of oral hygiene in head and neck cancer: results from International Head and Neck Cancer Epidemiology (INHANCE) consortium

BACKGROUND Poor oral hygiene has been proposed to contribute to head and neck cancer (HNC) risk, although causality and independency of some indicators are uncertain. This study investigates the relationship of five oral hygiene indicators with incident HNCs. METHODS In a pooled analysis of 8925 HNC cases and 12 527 controls from 13 studies participating in the International Head and Neck Cancer Epidemiology Consortium, comparable data on good oral hygiene indicators were harmonized. These included: no denture wear, no gum disease (or bleeding), <5 missing teeth, tooth brushing at least daily, and visiting a dentist ≥once a year. Logistic regression was used to estimate the effects of each oral hygiene indicator and cumulative score on HNC risk, adjusting for tobacco smoking and alcohol consumption. RESULTS Inverse associations with any HNC, in the hypothesized direction, were observed for <5 missing teeth [odds ratio (OR) = 0.78; 95% confidence interval (CI) 0.74, 0.82], annual dentist visit (OR = 0.82; 95% CI 0.78, 0.87), daily tooth brushing (OR = 0.83, 95% CI 0.79, 0.88), and no gum disease (OR = 0.94; 95% CI 0.89, 0.99), and no association was observed for wearing dentures. These associations were relatively consistent across specific cancer sites, especially for tooth brushing and dentist visits. The population attributable fraction for ≤ 2 out of 5 good oral hygiene indicators was 8.9% (95% CI 3.3%, 14%) for oral cavity cancer. CONCLUSION Good oral hygiene, as characterized by few missing teeth, annual dentist visits, and daily tooth brushing, may modestly reduce the risk of HNC.

A comparative assessment of major international disasters: the need for exposure assessment, systematic emergency preparedness, and lifetime health care

BackgroundThe disasters at Seveso, Three Mile Island, Bhopal, Chernobyl, the World Trade Center (WTC) and Fukushima had historic health and economic sequelae for large populations of workers, responders and community members.MethodsComparative data from these events were collected to derive indications for future preparedness. Information from the primary sources and a literature review addressed: i) exposure assessment; ii) exposed populations; iii) health surveillance; iv) follow-up and research outputs; v) observed physical and mental health effects; vi) treatment and benefits; and vii) outreach activities.ResultsExposure assessment was conducted in Seveso, Chernobyl and Fukushima, although none benefited from a timely or systematic strategy, yielding immediate and sequential measurements after the disaster. Identification of exposed subjects was overall underestimated. Health surveillance, treatment and follow-up research were implemented in Seveso, Chernobyl, Fukushima, and at the WTC, mostly focusing on the workers and responders, and to a lesser extent on residents. Exposure-related physical and mental health consequences were identified, indicating the need for a long-term health care of the affected populations. Fukushima has generated the largest scientific output so far, followed by the WTCHP and Chernobyl. Benefits programs and active outreach figured prominently in only the WTC Health Program. The analysis of these programs yielded the following lessons: 1) Know who was there; 2) Have public health input to the disaster response; 3) Collect health and needs data rapidly; 4) Take care of the affected; 5) Emergency preparedness; 6) Data driven, needs assessment, advocacy.ConclusionsGiven the long-lasting health consequences of natural and man-made disasters, health surveillance and treatment programs are critical for management of health conditions, and emergency preparedness plans are needed to prevent or minimize the impact of future threats.

Mortality among World Trade Center rescue and recovery workers, 2002–2011

BACKGROUND Rescue and recovery workers responding to the 2001 collapse of the World Trade Center (WTC) sustained exposures to toxic chemicals and have elevated rates of multiple morbidities. METHODS Using data from the World Trade Center Health Program and the National Death Index for 2002-2011, we examined standardized mortality ratios (SMR) and proportional cancer mortality ratios (PCMR) with indirect standardization for age, sex, race, and calendar year to the U.S. general population, as well as associations between WTC-related environmental exposures and all-cause mortality. RESULTS We identified 330 deaths among 28,918 responders (SMR 0.43, 95%CI 0.39-0.48). No cause-specific SMRs were meaningfully elevated. PCMRs were elevated for neoplasms of lymphatic and hematopoietic tissue (PCMR 1.76, 95%CI 1.06-2.75). Mortality hazard ratios showed no linear trend with exposure. CONCLUSIONS Consistent with a healthy worker effect, all-cause mortality among responders was not elevated. There was no clear association between intensity and duration of exposure and mortality. Surveillance is needed to monitor the proportionally higher cancer mortality attributed to lymphatic/hematopoietic neoplasms.

Baseline Serum β-carotene Concentration and Mortality among Long-Term Asbestos-Exposed Insulators

Background: Although interventional trials demonstrated that moderate-dose β-carotene supplementation increases lung cancer mortality in smokers and asbestos-exposed workers, differences in serum concentrations in absence of supplementation have not been studied in asbestos-exposed workers. Methods: A mortality analysis was performed to assess the relationship of nonsupplemented serum β-carotene to all-cause and cancer mortalities using 1981 to 1983 serum β-carotene concentration measurements from 2,646 U.S. white male insulators (mean age, 57.7 years). Multivariable-adjusted Cox proportional hazard models that included terms for age, duration of asbestos exposure, smoking, season, and region were fitted to estimate mortality HRs and 95% confidence intervals (CI) according to serum β-carotene concentrations. Results: Median follow-up was 12.8 years and 984 (33.8%) subjects died during the follow-up period, including 415 deaths from overall cancer and 219 deaths from lung cancer. The overall mortality HR for a serum β-carotene increase of 10 μg/dL was 0.97 (95% CI, 0.96–0.99). Compared with the lowest quartile, HRs were 0.90 (95% CI, 0.76–1.07) for the second (38–65 μg/dL), 0.80 (95% CI, 0.67–0.96) for the third (66–104 μg/dL), and 0.63 (95% CI, 0.51–0.77) for the highest serum β-carotene quartile (≥105 μg/dL). There was no association between serum β-carotene and overall cancer mortality (HR, 1.00; 95% CI, 0.97–1.02) or lung cancer mortality (HR, 0.99; 95% CI, 0.96–1.02). Conclusions: Higher nonsupplemented serum β-carotene concentrations were negatively associated with all-cause mortality among asbestos-exposed individuals. Impact: Serum β-carotene can be a marker of one or more determinants of reduced mortality in asbestos-exposed workers. Cancer Epidemiol Biomarkers Prev; 24(3); 555–60. ©2014 AACR.

Prostate cancer characteristics in the World Trade Center cohort, 2002-2013.

An increased incidence of prostate cancer was reported in three cohorts of World Trade Center (WTC) respondents. It is uncertain whether this increase is because of WTC-related exposures or enhanced surveillance. Prostate cancer cases (2002–2013) were obtained from the WTC Health Program. Age, race, and Gleason score distribution were compared with New York State Cancer Registry cases from the same time period. Multivariate models were adjusted for age and race. Analyses of clinical characteristics of prostate cancer cases within the cohort were also carried out, adjusting for age, race, and WTC exposure categories. WTC respondents had a prostate cancer age-standardized rate ratio of 1.65 [95% confidence interval (CI): 1.37–1.93] compared with New York State; age-specific ratios were highest for ages 30–49 (2.28; 95% CI: 1.51–3.43), 70–74 (2.05; 95% CI: 1.03–4.10), and 80–84 years (5.65; 95% CI: 1.41–22.58). High WTC exposure was associated with advanced clinical stage (5.58; 95% CI: 1.05–29.76; Ptrend=0.03). WTC respondents continue to have a higher prostate cancer rate compared with New York State as a whole. Respondents with a higher WTC exposure level may have had more advanced clinical stage of prostate cancer.

Standardized cancer incidence disparities in Upper Manhattan New York City neighborhoods: The role of race/ethnicity, socioeconomic status, and known risk factors

We examined the effects of race/ethnicity and neighborhood, a proxy of socioeconomic status, on cancer incidence in New York City neighborhoods: East Harlem (EH), Central Harlem (CH), and Upper East Side (UES). In this ecological study, Community Health Survey data (2002–2006) and New York State Cancer Registry incidence data (2007–2011) were stratified by sex, age, race/ethnicity, and neighborhood. Logistic regression models were fitted to each cancer incidence rate with race/ethnicity, neighborhood, and Community Health Survey-derived risk factors as predictor variables. Neighborhood was significantly associated with all cancers and 14 out of 25 major cancers. EH and CH residence conferred a higher risk of all cancers compared with UES (OR=1.34, 95% CI 1.07–1.68; and OR=1.39, 95% CI 1.12–1.72, respectively). The prevalence of diabetes and tobacco smoking were the largest contributors toward high cancer rates. Despite juxtaposition and similar proximity to medical centers, cancer incidence disparities persist among EH, CH, and UES neighborhoods. Targeted, neighborhood-specific outreach may aid in reducing cancer incidence rates.

Access to properly fitting personal protective equipment for female construction workers

BACKGROUND Previous literature suggests that most personal protective equipment (PPE) for construction is designed for males and does not accommodate female anthropometry. We conducted a pilot study to identify whether female construction workers currently have adequate access to properly fitting PPE. METHODS Semi-structured focus group interviews were conducted with union female carpenters, laborers, and ironworkers. Researchers coded focus group transcriptions and extracted major themes using thematic framework analysis. RESULTS Participants (n = 23) had a mean of 15.1 years of construction experience (range 3-34.5 years). A majority reported fit problems for many types of PPE (gloves, harnesses, safety vests, work boots, outerwear), generally noting that the equipment provided by contractors was too large. Other emergent themes included female workers purchasing their own PPE, exposure to various safety hazards from poorly fitted PPE, and perceived indifferent safety culture. CONCLUSIONS Female construction workers continue to have difficulty accessing properly fitting PPE. Am. J. Ind. Med. 59:1032-1040, 2016.

Hormone factors play a favorable role in female head and neck cancer risk

Due to lower female incidence, estimates of exogenous and endogenous hormonal factors in head and neck cancers (HNCs, comprising cancers of the oral cavity, oropharynx, hypopharynx, and larynx) among women have been inconsistent and unable to account for key HNC risk factors. We pooled data from 11 studies from Europe, North America, and Japan. Analysis included 1572 HNC female cases and 4343 controls. Pooled odds ratios (ORs) estimates and their 95% confidence intervals (CIs) were calculated using multivariate logistic regression models adjusting for tobacco smoking and alcohol drinking. Lower risk was observed in women who used hormone replacement therapy (HRT) (OR = 0.58; 95% CI: 0.34–0.77). Pregnancy (OR = 0.61; 95% CI: 0.42–0.90) and giving birth (OR = 0.59; 95% CI: 0.38–0.90) at <35 years of age were inversely associated with HNCs. An inverse association with HNC was observed with age at start of HRT use (OR = 0.59; 95% CI: 0.39–0.90) for each additional 10 years and with duration of use (OR = 0.87; 95% CI: 0.76–0.99 for every 3 years). Exogenous female hormone use is associated with a nearly twofold risk reduction in female HNCs. The lower female HNC incidence may, in part, be explained by endogenous and exogenous estrogen exposures.