Table 4.
Respiratory, cardiovascular, and haematological changes resulting from exposure to electronic waste
| Exposure setting | Exposed population | Control population | Toxic chemicals | Health outcomes | |
|---|---|---|---|---|---|
| Respiratory | |||||
| Zeng et al (2017)38 | Cross sectional: exposed town vs reference town, China | 100 preschool children aged 5–7 years | 106 preschool children aged 5–7 years | Lead and cadmium | Blood lead=5·53 μg/dL vs 3·57 μg/dL (p<0·001), blood cadmium=0·58 μg/L vs 0·57 μg/L (p>0·05), lower Hb, HCT, higher platelet, thrombocytosis in exposed (all p<0·05). FVC=1·23 L vs 1·33 L, FEV1 =1·16 L vs 1·24 L (both p<0·01), FVC/FEV1=0·95% vs 0·96% (p>0·05). No association between blood lead, cadmium, platelet, and FVC, FEV1 (p>0·05). 1 g/L Hb decline associated with 5 mL and 4 mL decrease in FVC and FEV1, respectively (p<0·05). |
| Zeng et al (2017)87 | Cross sectional: exposed town vs reference town, China | 100 preschool children aged 5–7 years | 106 preschool children aged 5–7 years | Not assessed | FVC=1·23 L vs 1·33 L, FEV1=1·16 L vs 1·24 L (both p<0·05). Birthweight=3·07 kg vs 3·25 kg, height=111·03 cm vs 112·56 cm, chest circumference=52·63 cm vs 53·42 cm (all p<0·05). Lung function associated with birthweight (FVC β=0·13, FEV1 β=0·15), chest circumference (FVC β=0·16, FEV1 β=0·15; all p<0·05). |
| Zeng et al (2016)39 | Cross sectional: exposed town vs reference town, China | 300 children aged 3–8 years | 170 children aged3–8 years | Lead, cadmium, chromium, and manganese | Blood lead=6·24 μg/dL vs 4·75 μg/dL, blood cadmium=0·57 μg/L vs 0·50 μg/L, lead in PM2·5=153 ng/m3vs 80 ng/m3, cadmium in PM2·5=5·58 ng/m3vs 3·48 ng/m3 (all p<0·05), no differences in blood chromium and manganese (p>0·05). Increased cough, dyspnoea, phlegm, wheeze in exposed (p<0·05). Blood chromium associated with cough (AOR=1·91, 95% CI 1·17 to 3·13), Blood manganese associated with wheeze (AOR 2·91, 95% CI 1·09 to 7·78), elevated blood lead (>5 μg/dL) associated with asthma (AOR 9·50, 95% CI 1·16 to 77·49; all p<0·05). |
| Zhang et al (2019)86 | Cross sectional: exposed town vs reference town, China | 110 preschool children aged 2–7 years | 112 preschool children aged 2–7 years | Not assessed | PM2·5=39·06 μg/m3vs 26·68 μg/m3, PM2·5 CDI=1·40 ng/kg per day vs 0·88 ng/kg per day (p<0·001). Saliva SAG=5·05 ng/mL vs 8·68 ng/mL, CDI negatively correlated with saliva SAG level (B=−1·21, 95% CI −2·29 to −0·13; p<0·05). Elevated white blood cells, neutrophils, monocytes, IL-8, and TNF-α in exposed (p<0·001), higher monocyte count associated with lower saliva SAG level (B=−6·25, 95% CI −11·76 to −0·75; p<0·05). |
| Cardiovascular | |||||
| Lu et al (2018)47 | Cross-sectional: exposed town vs reference town, China | 337 preschool children aged 3–7 years | 253 preschool children aged 3–7 years | Lead | Blood lead=7·14 vs 3·91 μg/dL; p<0·001, elevated SBP, PP, TG, LDL/HDL and Tc/HDL ratio, lower HDL (all p<0·05). Higher Lp-PLA2=93·29 ng/mL vs 79·65 ng/mL, IL-6=10·00 pg/mL vs 1·61 pg/mL, IL-8=2·38 pg/mL vs 1·59 pg/mL, and TNF-α=2·36 pg/mL vs 1·86 pg/mL (all p<0·05). Elevated blood lead associated with higher Lp-PLA2, IL-6 (rs=0·20 and rs=0·59), (TG B=0·08, 95% CI 0·02 to 0·14) and lower HDL (B=−0·07, 95% CI −0·12 to −0·01), PP (B=−3·10, 95% CI −1·37 to −1·82; all p<0·05). Lp-PLA2 negatively associated with PP and HDL (B=−2·09 and B=−0·05; p<0·01). |
| Zheng et al (2019)48 | Cross-sectional: exposed town vs reference town, China | 105 preschool children aged 3–7 years | 98 preschool children aged 3–7 years | Lead and PAHs | Blood lead=7·23 μg/dL vs 3·91 μg/dL and elevated urinary ∑OHPAHs, ∑OHNap and ∑OHFlu in exposed group (all p<0·05). Increased monocytes, neutrophils, leukocytes, serum S100A8/A9 and IL-6, IL12p70, IP-10, CD4+ T cell percentage in exposed. Elevated blood lead, urinary 2-OHNap and ∑OHFlu associated with higher levels of IL-6, IL12p70, IP-10, CD4+ T cell percentage, neutrophil and monocyte counts (all p<0·05). |
| Cong et al (2018)88 | Cross-sectional: exposed town vs reference town (and non-native), China | 228 preschool children aged 3–6 years | 104 native and 91 non-native preschool children aged 3–6 years | PM2·5, PM10, SO2, NO2, CO, and O3 | Higher concentrations of PM2·5, PM10, SO2, NO2, CO among exposed (data not shown, all p<0·001). Median heart rate=106 bpm vs 102 bpm and 100 bpm, plasma norepinephrine=4·42 nmol/L vs 3·88 nmol/L and 3·44 nmol/L (both p<0·01). Positive association between PM2·5, PM10, SO2, NO2and plasma norepinephrine, PM2·5, PM10, SO2, NO2,CO related to increase heart rate (p<0·05). |
| Gangwar et al (2019)58 | Cross-sectional: exposed vs residential, commercial, and vehicular vs residential, India | 28 local adult residents aged >18 years | 50 adults from residential, commercial, and vehicular sites and 54 adults from residential sites (both groups aged >18 years) | PM10, lead, copper, zinc, nickel, and chromium | PM10=243 μg/m3vs 233 μg/m3vs 193 μg/m3. Elevated zinc, lead, chromium, nickel, copper in blood, and PM10 among exposed, positive correlation between blood and air heavy metals (r=0·58–0·98; p<0·05). HTN=68% vs 44% vs 32% (p<0·05), positive correlation between ambient PM10with mean SBP and DBP (r=0·62 and 0·67; p<0·05), elevated PM10 related to low SpO2 (r=−0·78; p<0·05). BMI and HTN positively correlated (data not shown). |
| Burns et al (2016)89 | Cross-sectional: e-waste recycling activity, Ghana | 57 e-waste recyclers, aged 18–61 years | None | Not assessed | High exposures to noise=43·5%, moderate to high levels of stress: mean PSS score=25 of 40. Positive correlation between noise and heart rate (ρ=0·46; p<0·001), 1 dB increase in noise associated with a 0·17 increase in heart rate (p<0·01). |
| Haematological | |||||
| Dai et al (2017)43 | Cross-sectional: exposed town vs reference town, China | 332 preschool children aged 2–6 years | 152 preschool children aged 2–6 years | Lead | Blood lead=6·5 μg/dL vs 4·5 μg/dL, EPb=17·0 μg/dL vs 11·9 μg/dL (both p<0·001), lower median erythrocyte CR1 expression=6257 vs 8163 (p<0·01). Elevated erythrocyte lead and blood lead negatively associated with HCT, MCV, Hb, MCH, and MCHC (all p<0·05). High blood lead (>7·00) and erythrocyte lead (>18·6) associated with lower erythrocyte CR1 expression (βQ4=−0·16, 95% CI −0·32 to −0·008) and (βQ4=−0·19, 95% CI −0·35 to −0·03; both p<0·05). |
| Zeng et al (2018)44 | Cross sectional: exposed town vs reference town, China | 331 preschool children aged 3–7 years | 135 preschool children aged 3–7 years | Lead | Blood lead=5·64 μg/dL vs 3·68 μg/dL (p<0·01), higher median PLT, PCT, MPV, P-LCR level among exposed (p<0·01). Positive correlation between blood lead and PLT (r=0·10), PCT (r=0·12), MPV (r=0·11), P-LCR (r=0·09), child residence in exposed associated with PLT (R2=0·07), PCT (R2=0·11), MPV (R2=0·03; all p<0·05). |
| Zhang et al (2017)45 | Cross sectional: exposed group vs reference group, China | 153 preschool children aged 3–7 years | 141 preschool children aged 3–7 years | Lead and cadmium | Blood lead=10·34 μg/dL vs 8·30 μg/dL, blood cadmium=2·39 μg/L vs 1·79 μg/L (both p<0·001). Higher mean monocytes, eosinophils, neutrophils, basophils, and lower NK cells among exposed (all p<0·05). Blood lead escalated counts in monocytes (β=0·08), eosinophils (β=0·08), basophils (β=0·01), monocyte percentage (β=0·77) and decline neutrophils percentage (β=−4·15). Blood cadmium increase neutrophils percentage and counts (β=3·92 and 0·66; all p<0·05). |
| Dai et al (2019)64 | Cross-sectional: exposed area vs reference area China | 118 preschool children aged 2–7 years | 121 preschool children aged 2–7 years | PAHs | Urinary ∑OH-PAHs=3·05 μg/mmol cre vs 1·76 μg/mmol cre, ∑OHNa=1·48 μg/mmol cre vs 0·75 μg/mmol cre, ∑OHPh=0·94 μg/mmol cre vs 0·62 μg/mmol cre (all p<0·001). Increased cytokines (IL-1β=0·43 pg/mL vs 0·25 pg/mL, IP-10=28·5 pg/mL vs 25·5 pg/mL), lymphocyte ratio, platelet count, PCT and PLR in exposed (all p<0·01). ∑OH-PAHs negatively associated with MPV, PDW, P-LCR, MPVP and positively associated with platelet count, PLR, ∑OHNa positively associated with IL-1β mediated through MPV, PDW, P-LCR, PLR (all p<0·05). |
| Xu et al (2015)70 | Cross-sectional: exposed town vs control town, China | 40 local residents aged 15–65 years | 15 local residents aged 15–65 years | PCBs and PBDEs | ∑PCBs=964 ng/g vs 68 ng/g (p<0·0001), ∑PBDEs 139 ng/g vs 76 ng/g (p>0·05). Lower monocyte, lymphocyte and higher neutrophil, Hb, platelets among exposed group (all p<0·05). ∑PCBs negatively correlated with monocyte (r=−0·67), lymphocyte (r=−0·38) and positively correlated with neutrophils (r= 0·58), Hb (r=0·35), ∑PBDEs positively correlated with WBC (r=0·34), Hb (r=0·34), and platelets (r=0·37). |
| Chen et al (2019)46 | Experimental: exposed vs reference groups, China | 158 hospitalised patients aged 4–85 years | 109 hospitalised patients aged 4–85 years | Lead and cadmium | Blood lead=8·7 μg/dL vs 5·1 μg/dL (p<0·001), cadmium=2·1 μg/L vs 2·6 μg/L (p>0·05), RBC=4·5 × 103 cell per μL vs 4·2 × 103 cells per μL, Hb=137·0 g/dL vs 123·0 g/dL (both p<0·05), platelets (p>0·05). Blood lead positively correlated with blood cadmium (r=0·11; p<0·05). Positive correlation between blood lead and RBC (r=0·17), Hb (r=0·12, both p<0·05). |
Hb=haemoglobin. HCT=haematocrit. FVC=forced vital capacity. FEV1=forced expiratory volume in 1 s. AOR=adjusted odds ratio. SAG=salivary agglutinin. CDI=chronic daily intake. IL=interleukin. TNF=tumour necrosis factor. SBP=systolic blood pressure. PP=pulse pressure. Tc=total cholesterol. TG=triglyceride. Lp-PLA2=lipoprotein-associated phospholipase A2. PAH=polycyclic aromatic hydrocarbon. ∑OHPAH =total hydroxylated polycyclic aromatic hydrocarbon. ∑OHNap=total hydroxylated naphthalene. ∑OHFlu=total hydroxylated fluorene. Bpm=beats per min. HTN=hypertension. PSS=perceived stress scale. SpO2=blood oxygen level. dB=decibel. DBP=diastolic blood pressure. BMI=body-mass index. EPb=erythrocyte lead. CR1=complement receptor. MCV=mean corpuscular volume. MCH= mean corpuscular haemoglobin. MCHC=mean corpuscular haemoglobin concentration. PLT=platelet count. PCT=plateletcrit. cre=creatinine. MPV=mean platelet volume. P-LCR=platelet large cell ratio. NK=natural killer. PLR=platelet count to lymphocyte count. PDW=platelet distribution width. MPVP=mean platelet volume to platelet count. ∑PBDEs=polybrominated diphenyl ether. RBC=red blood cells.