Refinery operations have been associated with a wide variety of atmospheric emissions consisting of criteria air pollutants, volatile organic components, hazardous air pollutants as well as other pollutants. With approximately 100 oil refineries in the Wider Caribbean region (WCR), hydrocarbons in this region pose significant environmental and human health risks. One of the oldest and largest refineries in the WCR is the Isla Refineriá, which is located on the island of Curaçao, and has been the basis of historical debates and conflict between the public and the local government over the environmental and human health risks. This research aims to establish baseline levels of ambient petrochemical emissions in Curaçao, specifically polycyclic aromatic hydrocarbons (PAHs), inhalable particulate matter (PM10) and sulfur dioxide (SO2), and to evaluate through comparative literature analysis and recommended public health guidelines the potential health risks in Curaçao. In addition, source elucidation of PAHs was conducted using concentration profiles, distribution profiles, binary diagnostic ratios and factor analysis. Passive air samplers with polyurethane foam collection disks (PAS-PUFs) were deployed in 2011 (n=43) and in 2014 (n=30) to measure ambient PAH concentrations. Ambient PAH concentrations ranged from 1.2 ng/m3 in 2011 and 27.3 to 660.1 ng/m3 in 2014, demonstrating no temporal differences. However, there were highly significant spatial differences, with the samples downwind of the refinery having significantly higher ambient PAH concentrations than those upwind in 2014. Source elucidation revealed the ambient PAHs were dominated by petrogenic emission sources (i.e., refinery) in the 2011 and the 2014 downwind samples, whereas the 2014 upwind locations were equally influenced by both petrogenic (i.e., refinery) and pyrogenic (i.e., vehicle emissions) sources. Available hourly, daily and monthly PM10 and SO2 measurements were downloaded from June 2010 through December 2014 from two local air monitoring stations. Concentrations of both PM10 and SO2 in Curaçao are among the highest reported globally, demonstrating an increasing trend over time and exceed current public health guidelines recommended by local and international agencies. It is plausible that the residents of Curaçao may experience health effects often associated with PM10 and SO2, however the epidemiological evidence is inadequate to infer causality between health effects and long-term exposures. Using the USEPA’s risk analysis methodology the resulting cumulative lifetime cancer risk estimates from PAH inhalation were below the level of concern (1.0 x 10-4). In contrast, by evaluating the potency adjusted concentrations relative to the most toxic compound (benzo[a]pyrene), age class (children and adults) extrapolated and site specific risks indicated levels exceeding the upper bound acceptable risk (1.0 x 10-4) by almost two orders of magnitude suggesting the need for remediation.

Background: Most countries of sub-Saharan Africa (SSA) are experiencing a high rate of ur­banization accompanied with unplanned development resulting into sprawl of slums. The weath­er patterns and air pollution sources in most urban areas are changing with significant effects on health. Studies have established a link between environmental exposures, such as weather variation and air pollution, and adverse health outcomes. However, little is known about this relationship in urban populations of SSA where more than half the population reside in slums, or slum like conditions. A major reason for this is the lack of systematic collection of data on exposure and health outcomes. High quality prospective data collection and census registers still remain a great challenge. However, within small and spatially defined areas, dynamic cohorts have been established with continuous monitoring of health outcomes. Collection of environmental exposure data can complement cohort studies to investigate health effects in relation to environmental exposures. The objective of this research was to study the health effects of selected environmental exposure among the urban poor population in Nairobi, Kenya. Methods: We used the platform of the Nairobi Urban Health and Demographic Surveillance System (NUHDSS), including two nested research studies, to provide data on mortality and mor­bidity. The NUHDSS was established in two areas of Nairobi, Korogocho and Viwandani, in 2003 and provides a unique opportunity for access to longitudinal population data. In addition, we conducted real-time measurements of particulate matter (PM2.5) in the areas from February to October in 2013. We obtained meteorological measurements from the Moi Air Base and Nairobi airport weather stations for the study period. We also conducted a cross-sectional survey to estab­lish the communities’ perceptions about air pollution and its related health risks. Time series re­gression models with a distributed lag approach were used to model the relationship between weather and mortality. A semi-ecological study with group level exposure assignment to individuals was used to assess the relationship between child health (morbidity and mortality) and the extent of PM2.5 exposure. Results: There was a significant association between daily mean temperature and all-cause mor­tality with minimum mortality temperature (MMT) in the range of 18 to 20 °C. Both mortality risk and years of life lost analysis showed risk increases in relation to cold temperatures, with pronounced effect among children under-five. Overall, mortality risks were found to be high during cold periods of the year, rising with lower temperature from MMT to about 40% in the 0–4 age group, and by about v 20% among all ages. The results from air pollution assessment showed high levels of PM2.5 concentration exceeding World Health Organization (WHO) guideline limits in the two study ar­eas. The air pollution concentration showed similar seasonal and diurnal variation in the two slums. The majority of community residents reported to be exposed to air pollution at work, with 66% reporting to be exposed to different sources of air pollution. Despite the observed high level of exposure, residents had poor perception of air pollution levels and associated health risks. Children in the high-pollution areas (PM2.5≥ 25 μg⁄m3) were at significantly higher risk for morbidity (OR = 1.30, 95% CI: 1.13-1.48) and cough as the only form of morbidity (OR = 1.33, 95% CI: 1.15-1.53) compared to those in low-pollution areas. In addition, exposure to high levels of pollution was associated with high child mortality from all-causes (IRR=1.15, 95% CI: 1.03-1.28), and indicated a positive association to respiratory related mortality (IRR=1.10, 95% CI: 0.91-1.33). Conclusion: The study findings extend our knowledge on health impacts related to environmental exposure by providing novel evidence on the risks in disadvantaged urban populations in Af­rica. More specifically, the study illustrates the invisible health burden that the urban poor population are facing in relation to weather and air pollution exposures. The effect of cold on population is preventable. This is manifested by the effective adaptation to cold conditions in high-latitude Nordic countries by housing standards and clothing, as well as a well-functioning health system. Further, awareness and knowledge of consequences, and reductions in exposure to air pollution, are necessary to improve public health in the slum areas. In conclusion, adverse health impacts caused by environmental stressors are critical to assess further in disadvantaged populations, and should be followed by development of mitigation measures leading to improved health and well being in SSA.

Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic air pollutants formed during incomplete combustion and are ubiquitously distributed in the environment. To determine particle-bound PAHs in archived PM2.5 samples taken with low flow rate in Atlanta, a sensitive and robust method was developed for measuring 28 PAHs and methyl PAHs in PM samples using isotope dilution gas chromatography/high resolution mass spectrometry (GC/HRMS). The method was then used to analyze PM2.5 samples collected at three sites (rural, urban, suburban-highway) from the Assessment of Spatial Aerosol Composition in Atlanta (ASACA) network. Distinct seasonal and spatial variations were observed in PAH concentration. Particle-bound PAH levels were significantly higher in winter than in summer. The suburban-highway site had higher PM2.5-bound PAH concentration than did the urban site, and the rural site had the lowest PAH levels. Retene, a proposed biomass burning tracer, captured both the high leaves-grasses-bushes-branches burning season and the high wood burning months, suggesting that it might be a better marker for all biomass burning, while potassium ion might be a more specific tracer for wood burning. Human exposure to PAHs can be assessed by characterizing their hydroxy PAH (OH-PAH) metabolites in urine samples. A method was developed to measure 24 urinary OH-PAHs, metabolites of 8 parent PAHs, using enzymatic de-conjugation, automatic liquid-liquid extraction, and GC/HRMS. A study was then carried out to evaluating the variability of the urinary biomarker levels in a non-occupationally exposed non-smoking reference group. Levels of urinary PAH metabolites varied widely both within-subject and between-subjects and the within-day variance far exceeded the between-day variance. There were also considerable temporal correlations for these biomarkers. Sample size calculations were conducted and taking 24-hour voids would require the least number of subjects, which should be considered during epidemiological study design. Finally, a study was conducted to evaluate exposure to ambient PAHs in an urban setting among 8 non-occupationally exposed non-smoking volunteers employing both personal air sampling and urine biomonitoring. PAH levels varied largely in air samples taken at home, at work, and while driving or jogging. Monitoring urinary OH-PAH levels can capture both inhalation and dietary exposures. Total inhaled PAH was correlated with total excreted OH-PAHs, suggesting that by combining personal air sampling and biomonitoring, exposure to environmental PAHs can be well characterized even for low-level exposure.

<p>Traditional cooking using biomass is associated with adverse health consequences, local environmental degradation, and regional climate change. Improved stoves (ICS; liquefied petroleum gas (LPG), biogas, electric, efficient biomass) are heralded as a solution, but their adoption and use remains low. In the first chapter, I report on a series of pilot programs that utilized the marketing mix principles of promotion, product, price and place to increase stove sales in rural Inia. We found that when given a choice amongst products, households strongly preferred an electric stove over improved biomass-burning options. Households clearly identified price as a significant barrier to adoption, while provision of discounts (e.g., rebates given if households used the stove) or payments in installments were related to higher purchase. Collectively, these pilots point to the importance of continued and extensive testing of messages, pricing models, and responses to different stove types prior to scale-up. Thus, a one-size-fits-all approach will be unlikely to boost ICS adoption. </p><p>In the second and third chapters, I analyze the impact of mainly improved stove use on social, environmental, and health outcomes in rural India- first in a sample of biogas stove users in Odisha, India, and next with households in the Himalayan state of Uttarakhand. In both settings, ICS use was associated with reduced use of firewood, substantial time savings for primary cooks, and significant reduction in exposure to particulate matter and polycyclic aromatic hydrocarbons in household air. I find that ICS users in Odisha spend reduced time in the hospital with acute respiratory infection and reduced diastolic blood pressure, but no relationship with other health measurements. </p><p>In the third chapter, I also find significant reduction in exposure to personal air pollution. Using temperature sensors as objective stove use monitors for all stoves and heaters we find that households underreport use of improved and traditional stoves. </p><p>These papers provide encouraging evidence of potential for adoption of clean stove and a suite of benefits from clean stove use; however, in order to achieve recommended levels of air pollution additional policies may be needed.</p> / Dissertation

Recent occupational health studies have focused on dermal exposure at the hands, but have been unable to accurately express dose without knowing the HSA. There is no standard method to calculate HSA, though some researchers have derived HSA formulas based on dimensions from a Taiwanese population. This research paper describes a shortcut method to estimate the hand surface area (HSA) of a human hand from a two-dimensional hand tracing, and repeated a Taiwanese HSA study in order to explore the viability of its HSA formula in an American university population. A sample of nine adult men and nine adult women, each representing one third of the population percentile in hand length and hand breadth, were selected from a population within the University of South Florida in Tampa, FL. Hand length, breadth, a 2D hand tracing and a 3D light hand scan were collected from each participant. A linear regression was used to analyze the data sets and found a correlation (R=0.94) between 2D HSA and 3D HSA and slope of 2.6 (SD=0.2), with a regression equation of Y=2.6(X). A paired t-test was used to compare the Taiwanese HSA formula data against the 3D HSA. Results found that the Taiwanese data sets were significantly different from the 3D HSA (p<0.001), averaging 57 cm2 less than the 3D HSA. A jackknife analysis was implemented on the 2D HSA hand tracing data, and a paired t-test was performed between the jackknife estimate predictions and 3D HSA. Mean differences were not significantly different (p=0.97), with 0.87 cm2 difference between means. Results indicate that the USF Hand Tracing Method will provide a better estimate of HSA than the Taiwanese method, and can be used as a tool in HSA estimation.

In the UK, dipping sheep with pesticides for treating ectoparasites has been one of the main pesticide applications and it was compulsory between 1984 and 1991 when organophosphates (OPs) were the main ingredients of sheep dips. As a result many current elderly sheep farmers have been exposed to OPs. The acute health effects of many pesticides especially OPs are very well documented, while the effects of long-term exposure are still unclear. Difficulties in assessing past pesticide exposure have been suggested to be one of the main reasons for this uncertainty. The overall aim of this PhD was to develop long-term occupational pesticide exposure models for UK farmers, specifically for OP exposure among sheep dippers, and to apply them to the Study of Health in Agricultural Work (SHAW) in order to examine the associations between long-term pesticide exposure and neuropsychiatric ill-health. A comprehensive conceptual exposure model to assess pesticide exposure during sheep dipping was developed and included five sources of pesticide exposure; handling the concentrate, dipping sheep in the bath, handling sheep after dipping, disposal of sheep dip, and any incidental exposure. Dermal, ingestion and inhalation routes were described for each source and different modifying factors for each route were identified. A semi-quantitative exposure algorithm was developed and all sources, routes and modifying factors were assigned scores and weights by assessment of the literature and expert judgement. The new model was evaluated by comparing its estimates of diazinon exposure among dippers who participated in the Health and Sheep Dipping Survey (HSDS) with diazinon urinary metabolite levels in spot urines collected after the dipping session. The model estimates generally did not correlate well with metabolite levels though there was evidence of an association between total metabolites and ordinal categories of exposure intensity. The uncontrolled conditions of the HSDS and the lack of 24 hr urine collections may have contributed to these results. A probabilistic model was also developed from the conceptual model and indicated that although handling the concentrate and dipping sheep are the most important exposure sources, other sources like handling dipped sheep and disposal of sheep dip should not be neglected. This probabilistic model was applied to different scenarios: probabilistic estimates may give a more comprehensive description of exposures than deterministic estimates as they take into account all conceptual variables. Occupational pesticide exposure among UK farmers in the SHAW study was then estimated using simple surrogates and more sophisticated models. The validity of self-reported exposure history among SHAW farmers was investigated by making comparison with data collected contemporaneously by the June Census. Farmers recall was generally reliable especially for a specific type of livestock or crop rather than the number of livestock or acreage. Associations between screen-identified ill-health and pesticide exposure were only demonstrated by using more developed metrics. Exposure to pesticides but not specifically OPs in sheep farming was associated with neuropathy and Parkinsonism. Exposure to OPs in sheep dipping was associated with a decrease risk of dementia. Depression was not associated with any exposure. In conclusion, this thesis developed a comprehensive model for pesticide exposure from sheep dipping and simpler exposure models for other farming sectors. The application of these models to the SHAW study suggests that long term pesticide exposure among farmers mainly via sheep dipping may result in ill- health; however the associations between exposure and outcomes may only be revealed by the use of more sophisticated exposure models rather than simple exposure surrogates. The study also indicates that even the use of well-derived deterministic estimates might lead to exposure misclassification. This misclassification may be investigated by using probabilistic approaches.

Background Vanadium is an economically important mineral that is mined and processed at several international locations, including South Africa and the USA. Vanadium exists in several oxidative states, of which the pentavalent compounds are usually the most toxic. Vanadium pentoxide (V205) is pentavalent and is generated during various processing and metal alloy manufacturing processes. Occupational exposure may occur via inhalation of V205 fumes and particles, resulting primarily in adverse effects to the respiratory system. Currently, there is no evidence that vanadium is carcinogenic in humans, and it has never been reported in exposed humans. The International Agency for Research in Cancer (IARC) has classified V205 as possibly carcinogenic to humans, based on the increased incidence of bronchiolo-alveolar neo¬plasms observed in male and female mice and male rats in a study by the National Toxicology Program (NTP) of the US Department of Health and Human Services. The NTP study has prompted the international vanadium industry, embodied by Vanitec, the international association of vanadium producers, to request an epidemiological study with the aim of determining the potential association between cancer and occupational V205 exposure. Aim The aim of the study was to conduct a pilot retrospective case-control study to investigate the relationship between cumulative occupational exposure to V2O5 and the risk of developing cancer at two representative vanadium processing plants, one in SA and one in the USA. Methods All cases and controls were sourced from the industry’s current and past employee corps. Employees that could potentially have been exposed to V2O5 in the workplace for a period of at least 5 years were included in the study. Ethics approval for the study was obtained from the Ethics Committee of the University of Pretoria. Participation was on a voluntary basis, and all potentially eligible current workers were invited to participate. As many retirees and former employees as possible were traced and invited to participate, and eligible deceased employees that conformed to the inclusion and exclusion criteria were identified from lists provided by the companies involved. Potential participants were asked to grant informed consent to participate in the study. Health and lifestyle information, information on fuel use in the family home, and a personal job history were obtained by use of a structured questionnaire during a personal interview with a trained interviewer. Interviews were conducted from April to July 2004. The main inclusion criterion for both cases and controls was current or previous employment at the South African, or the USA vanadium processing facility included in the study. The disease case definition was histologically confirmed cancer. Exclusion criteria were: refusal of interview; less than 5 years in employment when V2O5 was produced at the plant; cause of death not ascertained, employment elsewhere in the vanadium industry, and exposure to a known carcinogenic agent during a period of employment elsewhere. Males and females were included and participants were not excluded on the basis of race or ethnicity. Employees of all ages were eligible. Exposure assessment at both plants was based on recorded V2O5 concentrations in personal air samples, the participant’s job history, the history of vanadium processing, the physical structure and work organisation at the processing plants. Historical V2O5 concentrations in air in the workplace were retrospectively estimated for those periods during which personal air sampling was not conducted. Historical concentrations were estimated by extrapolation from current (known) air concentrations, in conjunction with data on annual production volumes, personal experiences of occupational hygienists and plant managers at the plant, and historical records of plant upgrades, controls on emissions, changes in production processes and industrial incidents and accidents, where available at the plants. Exposure was expressed as the cumulative exposure (mg-years/m3) and the mean air concentration (mg/m3) of V2O5 to which participants had been exposed. Study participants were also classified into exposure categories based on their mean exposure concentrations. Results In total, 196 questionnaires were collected from eligible participants. The majority (94.4 per cent) were males. Smoking and the consumption of alcohol was fairly common amongst the study group, with 61 per cent of the participants being current or previous smokers, and 59.5 per cent indicating that they were drinking alcoholic drinks or beverages. The mean age (± SD) of the study group was 52.4 ± 10.2. The annual mean exposure of the study group during the period of employment was 0.02 ± 0.03 mg/m3 V2O5, and the mean cumulative exposure to V2O5 was 0.17 ± 0.46 mg-years/m3. Four (4) cancer cases were confirmed at the South African plant, and 6 at the USA plant: four adenocarcinomas (three each in the prostate and one in the colon); three squamous cell carcinomas (two each in the lung and one skin cancer); one renal cell cancer of the kidney, one seminoma of the testis, and one papillary urothelial cancer of the bladder. The occurrence of prostate and lung cancers were not unusual, giving the presence of risk factors such as relatively advanced age (for prostate cancer) and smoking (for lung cancer). The other types of cancer, and the ages at which cancer was most frequently diagnosed (the mean age at diagnosis of cancer was 58.5) were not remarkably different from those that were prominent in the cancer literature. An unusual cluster of specific types of cancer, or of any prominent and unusual organ involvement not associated with known non-occupational risk factors, was therefore not found in the case group. Conclusion The results of this study fail to indicate a statistically significant association between cancer and various indices of exposure to vanadium pentoxide. This conclusion is subject to a number of limitations and uncertainties arising from the small number of cases available for study, and limited follow-up of some participants. The potential association between exposure and cancer should be tested in a larger study group with more cancer cases, allowing more powerful statistical analyses, ideally multivariate logistic regression analysis. The study has confirmed the feasibility of the retrospective assessment of exposure to vanadium compounds in the vanadium processing industry, providing that the processing plant history covers detail of processing methodologies, physical structures, production volumes and work organisation, and providing that a detailed job history should be available for all potential participants. Confirmation of the cause of death and cancer status of previous employees was not practical in the South African scenario. An open case-control design nested in a prospective cohort should be more successful in the South African scenario, but also more expensive and results will only be available after an extended follow-up period. In the USA scenario tracing of previous employees, and access to cancer registries and death certificates should be more practical, and a retrospective case-control study should be possible. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / School of Health Systems and Public Health (SHSPH) / Unrestricted

Methicillin-resistant Staphylococcus aureus (MRSA) was originally recognized as a hospital acquired infection. However, it is now recognized that MRSA infections are frequently acquired in the community setting as well. As epidemiological studies and surveillance of MRSA continued over the past decade, agricultural sources of MRSA have also been recognized. Although direct person-to-person transmission of MRSA has been recognized as a major known route of transmission, a preliminary study has shown that aerosol exposures may also be an important mechanism of transmission, both occupationally to workers inside animal feeding operations and environmentally via exhaust ventilation to the outside e. In this study I aimed to 1) determine the concentration of viable MRSA inside and outside swine buildings known to be positive for MRSA, 2) determine the efficiency of the N95 respirator at protecting workers inside swine buildings, and 3) determine the efficiency of a biofilter unit at mitigating emissions of MRSA from a swine building. I hypothesize that remediation and control of airborne MRSA in animal feeding operations can be achieved by the appropriate use of N-95 respirators to protect workers and the addition of biofilters to the exhaust ventilation system to mitigate transmission of this emerging environmental contaminant to the outdoor environment. The results of the study indicate that MRSA in the respirable size range can be detected inside a swine building and 215 m downwind of the swine building. Aim 2 results indicated that the N95 respirator was efficient at protecting workers exposed to MRSA particles greater than 5 μm but not as effective with MRSA particles less than 5 μm. The results of aim 3 indicated that hardwood chips and western red cedar chips are efficient biofilter media for mitigating the emission of MRSA from a swine building. These studies showed that workers inside swine buildings and the outdoor environment can be protected against the transmission of MRSA with a respiratory program which includes the use of N95 respirators and biofilters as mitigation control measures.

Hypospadias is a congenital malformation that occurs in 0.3-1% of live births, in which the meatus (the urethral opening) is dorsally malpositioned. Uncorrected hypospadias can cause difficulties in urination, abnormal sexual function, and adverse psychological consequences; surgical correction, though generally successful, constitutes an economic burden for families. Several common classes of pesticides have demonstrated potential to disrupt normal endocrine hormones that regulate fetal genitourinary development. Past epidemiologic studies of pesticide exposure and risk of hypospadias have been limited by limited available data, small sample sizes, or poor ascertainment of pesticide exposure. The objective of this study was to examine the relationship between parental occupational pesticide exposure and risk of hypospadias in their offspring; and further, to assess whether addition of residential pesticide exposure data is feasible and contributes to overall pesticide exposure. We began by conducting a meta-analysis of the current literature, in which summary measures of occupation (such as census occupation code) had been used to assign pesticide exposure. We found elevated but marginally significant risks of hypospadias were associated with maternal occupational exposure (PRR of 1.36, CI = 1.04-1.77), and paternal occupational exposure (PRR of 1.19, CI= 1.00-1.41) in the previously published literature. We then used industrial hygienist review of occupational histories to estimate the relationship between pesticide exposure and risk of hypospadias. We found that maternal occupational exposure to any pesticides (yes/no) was not associated with an increased risk of hypospadias (OR = 0.83, 95% CI = 0.6-1.1), cumulative insecticide (OR = 1.09; 95% CI = 0.9- 1.3), herbicide (OR = 1.05; 95% CI = 0.9- 1.2), or fungicide (OR = 0.91; 95% CI = 0.7-1.2) exposure. These negative findings might be explained by a lack of relationship at the low levels of exposure observed in this study population, in which case another farm exposure could be related to hypospadias; or this negative finding may be due to exposure misclassification. Finally, we evaluated the feasibility and relevance of collecting residential pesticide exposure and direct reports of occupational exposure from fathers. Residential pesticide use during the six months prior to pregnancy and during pregnancy was common among control mothers: 45% reported that their home had been treated for insect or rodent pests; 47% reported that their lawn or garden had been treated for weeds or insect pests; 16% used a lawn service; 26% reported that a pet had been treated for fleas, ticks, or mites (including flea and tick preventives); 17% reported community-wide sprayings for pests; and 16% reported that their workplaces were treated for pests. Case mothers were more likely to report that their home had been treated of insect or rodent pests (50%) or that a pet had been treated for fleas, ticks, or mites (36.5%). Our results suggest that collection of information on residential pesticide use is feasible, and the impact of residential pesticide use on birth defects risk should be assessed in future studies.

For this work the Geo-referenced Regional Exposure Assessment Tool for European Rivers (GREAT-ER) was developed further to support river basin management and the implementation process within the EU Water Framework Directive (WFD). This was achieved through predicting spatially resolved pharmaceutical exposure concentrations in whole watersheds. A major focus of this thesis has been placed on modeling challenging watersheds, whereby challenging can refer to hydrological conditions in a watershed as well as to specific emission patterns that occur within the watersheds. The adapted methodology improves the prediction accuracy in such watersheds with GREAT-ER with respect to pharmaceutical exposures, but can also lead to improved results in other application areas. The possibilities of the latest model version are demonstrated by the extensive inclusion of local and regional conditions. In watersheds with highly variable and seasonally changing hydrological situations, GREAT-ER has been applied satisfactorily for the first time, and additionally, the developed approach can be transferred to equivalent watersheds worldwide. Comparison with monitoring data confirms that some of the adjustments have resulted in significantly improved model predictions, especially when hydrological and local conditions are specifically addressed. For example, explicit consideration of local drug emissions from hospitals or private medical practices (e.g., for x-ray contrast agents) can improve predictions at the local scale without compromising regional exposure estimates. Pharmaceuticals that have low concentrations and are barely detectable with established analytical methods can be evaluated with model simulations. In addition, current management strategies implemented under the WFD has been replicated and evaluated. These management scenarios simulated with the model allow an a priori evaluation of risk reduction measures. In combination with targeted monitoring approaches, it was shown that the GREAT-ER model can serve as a valuable tool for exposure and risk assessment of pharmaceuticals even in challenging watersheds. This and the useful combination of targeted monitoring and GREAT-ER simulations and the ability of the modeling approach to predict the expected range of spatial surface water concentrations is demonstrated by three selected journal articles.