The long-term respiratory health effects of the herbicide, paraquat, among Western Cape workers

Objective: Paraquat is a commonly used herbicide worldwide and is a well-documented cause of pulmonary fibrosis in studies of laboratory animals and in humans following high dose exposure (usually accidental or as parasuicide). The respiratory effects of long-term, low dose paraquat exposure have not been fully evaluated. We set out to evaluate the possible effects of paraquat spraying among deciduous fruit farm workers in the Western Cape, South Africa. Methods: A cross-sectional study of 126 workers was performed. Administered questionnaires generated information on exposure, respiratory symptoms and confounding variables. Spirometry and gas transfer were measured and chest radiographs performed. Oxygen desaturation on exercise testing was by oximetry during a modified stage one exercise test. Results: No association was found between long-term paraquat exposure and reported symptoms, spirometry (FVC, FEVl, FEVl/FVC) and gas transfer (TLco and Kco) or chest radiography. Multivariate analysis showed a significant relationship between measures of long-term paraquat exposure and arterial oxygen desaturation during exercise (p < 0.05). Conclusion: Previous studies have also not shown a significant relationship between measures of paraquat exposure and standard tests of lung function. Arterial oxygen desaturation during exercise represents a more sensitive test. Our findings indicate that working with paraquat under usual field conditions for a long period is associated with abnormal exercise physiology in a dose dependant fashion

The relationship between reproductive outcome measures in DDT exposed malaria vector control workers: a cross-sectional study

BACKGROUND: The utility of blood reproductive endocrine biomarkers for assessing or estimating semen quality was explored. METHODS: A cross-sectional study of 47 DDT exposed malaria vector control workers was performed. Tests included blood basal and post gonadotrophin releasing hormone (GnRH), lutenizing hormone (LH), follicle stimulating hormone (FSH), testosterone, sex hormone binding globulin (SHBG), estradiol (E2) and inhibin; a questionnaire (demographics and general medical history); a physical examination and semen analysis. Semen parameters were determined using either/or or both WHO or the strict Tygerberg criteria. Relationships between semen parameters and endocrine measures were adjusted for age, duration of abstinence before sampling, presence of physical abnormalities and fever in the last two months. All relationships between specific endocrine hormones were adjusted for age and basal SHBG. RESULTS: Multiple logistic regression showed a consistent positive relationship (prevalence odds ratio (POR) = 8.2, CI:1.4–49.2) between low basal inhibin (<100 pg/ml) and low semen count (< 40 million) and density (< 20 million/ml); consistent positive, but weaker relationships (1> POR < 2) between abnormally low semen count as well as density and baseline and post GnRH FSH; and positive relationships (POR = 37, CI:2–655) between the prevalence of high basal estradiol (> 50 pg/ml) and abnormal morphology (proportion < 5%) and low motility (proportion <50%). Most of the expected physiological relationships between specific endocrines were significant. CONCLUSION: The study has demonstrated that low basal inhibin, elevated basal FSH and high basal E2 can serve as markers of impaired semen quality

Exposure to CCA-treated wood amongst food caterers and residents in informal areas of Cape Town

We investigated the absorption of chromium, copper and arsenic released from treated wood used by street food caterers and household residents in an informal urban area and a peri-urban area in Cape Town, South Africa. Participants (n=78) selected included an equal number of caterers and residents in each area. All participants answered an exposure questionnaire and were tested for urinary chromium, copper and arsenic, while the urine of 29 participants was also tested for toxic arsenic. Urinary chromium and arsenic exceeded the environmental exposure limit in 12% and 30% of participants, respectively. Toxic arsenic was detected in 30% of samples of which 24% exceeded the environmental exposure limit of 6.4 ?g/g creatinine. Urinary chromium, copper, arsenic and toxic arsenic levels were not significantly different between participants from the two areas or between caterers and household residents, controlling for confounding effects. The study provides evidence of chromium and arsenic exposure amongst both informal caterers and household residents, which requires further investigation

Relationship between firewood usage and urinary Cr, Cu and As in informal areas of Cape Town

OBJECTIVES: The study investigated whether wood usage by informal food vendors and household residents in Cape Town results in the absorption of arsenic (As), chromium (Cr) and copper (Cu) owing to release of these metals in the burning of chromated copper arsenate (CCA)-treated wood. METHODS: The participants (N=78) selected included an equal number of food vendors and non-vendors from 2 informal settlements. All participants answered a questionnaire concerning exposure and were tested for urinary Cr, Cu and As, while the urine of 29 participants was also tested for toxic As (As(tox)). RESULTS: Multivariate analysis showed that the time spent in close proximity to the wood, as well as the quantity of wood used for cooking and for household use, was weakly positively associated with urinary levels of As, Cr and the sum of As, Cr and Cu. CONCLUSIONS: The study provides evidence that use of wood likely to contain CCA as a fuel for informal food outlets and household purposes may increase the absorption of inorganic As, Cu and Cr

Knowledge and attitudes in the rural Western Cape towards pesticides in water sources

There is a need for pesticide water monitoring in South Africa and for community awareness with regard to chemical contamination of rural water sources. The results of two descriptive studies in the rural Western Cape are reported. One assessed water usage and the knowledge, attitudes and practices in relation to water of farm residents (229 participants from 60 farms) in the Slanghoek Valley, Hex River Valley and Grabouw (KAP) and the other (monitoring capacity survey), investigated water usage and the capacities of rural communities (63 farm residents from 16 farms in three local authorities and 8 environmental health officers (EHOs) from 7 local authorities) to conduct monitoring of pesticides in rural water sources. Most farm residents in both surveys identified protected sources such as groundwater from springs and boreholes (30 to 60%), and water from mountain dams (40 to 65%), as the most important sources for drinking and other domestic purposes. Many (> 40%), however, also reported farm dams. For use in the field (both drinking and other), potentially contaminated sources (river, subsurface drains, dams) were more frequently reported. Forty-eight percent of participants also reported swimming in farm dams. Other water sources reported included municipal, rain and canal water. In the monitoring capacity survey, 27 % reported using untapped water. About a third of respondents in the KAP survey reported living within 10 m of the nearest site of spraying and many used pesticides at home for pest control (41%) and in the garden (33%). While almost all participants (> 90%) in both surveys were aware that pesticides and polluted water could be harmful, many did not identify health effects (20%) especially chronic effects (91%) or reported no training (37%) in health effects. In all 7 districts surveyed in the monitoring capacity survey, water sources on farms are tested by EHOs. Only 3 (37%) respondents felt that there were enough persons conducting water monitoring in their area. Only 1 respondent reported that pesticides were monitored, and only in request to a complaint. Three state laboratories, that did not have the analytical capacity to conduct routine pesticide water monitoring at low (< 0.1 mg/&#8467;) detection limits, were identified as conducting water analyses. The study found that farm residents in the Western Cape are potentially exposed to pesticides through various environmental routes including water. This emphasises the need to monitor water for pesticides in the Western Cape, but in order to do this, human and laboratory resources and capacities to conduct routine pesticide water monitoring need to be increased. Water SA Vol.30(1): 43-5

Knowledge and attitudes in the rural Western Cape towards pesticides in water sources

There is a need for pesticide water monitoring in South Africa and for community awareness with regard to chemical contamination of rural water sources. The results of two descriptive studies in the rural Western Cape are reported. One assessed water usage and the knowledge, attitudes and practices in relation to water of farm residents (229 participants from 60 farms) in the Slanghoek Valley, Hex River Valley and Grabouw (KAP) and the other (monitoring capacity survey), investigated water usage and the capacities of rural communities (63 farm residents from 16 farms in three local authorities and 8 environmental health officers (EHOs) from 7 local authorities) to conduct monitoring of pesticides in rural water sources. Most farm residents in both surveys identified protected sources such as groundwater from springs and boreholes (30 to 60%), and water from mountain dams (40 to 65%), as the most important sources for drinking and other domestic purposes. Many (> 40%), however, also reported farm dams. For use in the field (both drinking and other), potentially contaminated sources (river, subsurface drains, dams) were more frequently reported. Forty-eight percent of participants also reported swimming in farm dams. Other water sources reported included municipal, rain and canal water. In the monitoring capacity survey, 27 % reported using untapped water. About a third of respondents in the KAP survey reported living within 10 m of the nearest site of spraying and many used pesticides at home for pest control (41%) and in the garden (33%). While almost all participants (> 90%) in both surveys were aware that pesticides and polluted water could be harmful, many did not identify health effects (20%) especially chronic effects (91%) or reported no training (37%) in health effects. In all 7 districts surveyed in the monitoring capacity survey, water sources on farms are tested by EHOs. Only 3 (37%) respondents felt that there were enough persons conducting water monitoring in their area. Only 1 respondent reported that pesticides were monitored, and only in request to a complaint. Three state laboratories, that did not have the analytical capacity to conduct routine pesticide water monitoring at low (< 0.1 mg/l) detection limits, were identified as conducting water analyses. The study found that farm residents in the Western Cape are potentially exposed to pesticides through various environmental routes including water. This emphasises the need to monitor water for pesticides in the Western Cape, but in order to do this, human and laboratory resources and capacities to conduct routine pesticide water monitoring need to be increased

Ambient Air Pollution and Cardiorespiratory Outcomes amongst Adults Residing in Four Informal Settlements in the Western Province of South Africa

Few studies have investigated the relationship between ambient air pollution and cardiorespiratory outcomes in Africa. A cross-sectional study comprising of 572 adults from four informal settlements in the Western Cape, South Africa was conducted. Participants completed a questionnaire adapted from the European Community Respiratory Health Survey, and the National Health and Nutrition Examination Survey questionnaire. Exposure estimates were previously modelled using Land-Use Regression for Particulate Matter (PM2.5) and Nitrogen Dioxide (NO2) at participants&rsquo; homes. The median age of the participants was 40.7 years, and 88.5% were female. The median annual NO2 level was 19.7 &micro;g/m3 (interquartile range [IQR: 9.6&ndash;23.7]) and the median annual PM2.5 level was 9.7 &micro;g/m3 (IQR: 7.3&ndash;12.4). Logistic regression analysis was used to assess associations between outcome variables and air pollutants. An interquartile range increase of 5.12 &micro;g/m3 in PM2.5 was significantly associated with an increased prevalence of self-reported chest-pain, [Odds ratio: 1.38 (95% CI: 1.06&ndash;1.80)], adjusting for NO2, and other covariates. The study found preliminary circumstantial evidence of an association between annual ambient PM2.5 exposure and self-reported chest-pain (a crude proxy of angina-related pain), even at levels below the South African National Ambient Air Quality Standards

Current use pesticides in soil and air from two agricultural sites in South Africa: Implications for environmental fate and human exposure

Concerns about the possible negative impacts of current use pesticides (CUPs) for both the environment and human health have increased worldwide. However, the knowledge on the occurrence of CUPs in soil and air and the related human exposure in Africa is limited. This study investigated the presence of 30 CUPs in soil and air at two distinct agricultural sites in South Africa and estimated the human exposure and related risks to rural residents via soil ingestion and inhalation (using hazard quotients, hazard index and relative potency factors). We collected 12 soil and 14 air samples over seven days during the main pesticide application season in 2018. All samples were extracted, purified and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry. In soils, nine CUPs were found, with chlorpyrifos, carbaryl and tebuconazole having the highest concentrations (up to 63.6, 1.10 and 0.212 ng g-1, respectively). In air, 16 CUPs were found, with carbaryl, tebuconazole and terbuthylazine having the highest levels (up to 25.0, 22.2 and 1.94 pg m-3, respectively). Spatial differences were observed between the two sites for seven CUPs in air and two in soils. A large dominance towards the particulate phase was found for almost all CUPs, which could be related to mass transport kinetics limitations (non-equilibrium) following pesticide application. The estimated daily intake via soil ingestion and inhalation of individual pesticides ranged from 0.126 fg kg-1 day-1 (isoproturon) to 14.7 ng kg-1 day-1 (chlorpyrifos). Except for chlorpyrifos, soil ingestion generally represented a minor exposure pathway compared to inhalation (i.e. &lt;5%). The pesticide environmental exposure largely differed between the residents of the two distinct agricultural sites in terms of levels and composition. The estimated human health risks due to soil inges-tion and inhalation of pesticides were negligible although future studies should explore other relevant pathways

Quantitative assessment of multiple pesticides in silicone wristbands of children/guardian pairs living in agricultural areas in South Africa

Little is known about personal and time-integrated exposure to past and current used pesticides in agricultural areas and within-family exposure similarities. We aimed to assess exposure to pesticides using silicone wristbands in child/guardian pairs living on farms and in villages within two agricultural areas in South Africa. Using silicone wristbands, we quantified 21 pesticides in child/guardian pairs in 38 households over six days in 2018. Levels (in ng/g wristband) of pesticides and their transformation products (12 current-use pesticides and nine organochlorine pesticides) were measured using GC-MS/MS. We assessed the correlation between pesticide levels and between household members using Spearman correlation coefficients (r(s)). Multivariable generalized least squares (GLS) models, using household id as intercept, were used to determine level of agreement between household members, exposure differences between children and guardians and exposure predictors (study area, household location [farm vs. village] and household pesticide use). We detected 16 pesticides with highest detection frequencies for deltamethrin (89%), chlorpyrifos (78%), boscalid (56%), cypermethrin (55%), and p,p'-DDT (48%). Most wristbands (92%) contained two or more pesticides (median seven (range one to 12)). Children had higher concentrations than guardians for four pesticides. Correlation between the pesticide levels were in most cases moderate (rs 0.30-0.68) and stronger in children than in guardians. Five pesticides showed moderate to strong correlation between household members, with the strongest correlation for boscalid (r(s) 0.84). Exposure differences between the two agricultural areas were observed for chlorpyri fas, diazinon, pmthiofos, cypermethrin, boscalid, p,p'-DDT and p,p'-DDE and within areas for cypermethrin. We showed that for several pesticides children had higher exposure levels than guardians. The positive correlations observed for child/guardian pairs living in the same household suggest non-occupational shared exposure pathways in these communities

Seasonal variations in air concentrations of 27 organochlorine pesticides (OCPs) and 25 current-use pesticides (CUPs) across three agricultural areas of South Africa

For decades pesticides have been used in agriculture, however, the occurrence of legacy organochlorine pesticides (OCPs) and current-use pesticides (CUPs) is poorly understood in Africa. This study investigates air concentrations of OCPs and CUPs in three South African agricultural areas, their spatial/seasonal variations and mixture profiles. Between 2017 and 2018, 54 polyurethane foam-disks passive air-samplers (PUF-PAS) were positioned in three agricultural areas of the Western Cape, producing mainly apples, table grapes and wheat. Within areas, 25 CUPs were measured at two sites (farm and village), and 27 OCPs at one site (farm). Kruskal-Wallis tests investigated area differences in OCPs concentrations, and linear mixed-effect models studied differences in CUPs concentrations between areas, sites and sampling rounds