Table 1: Studies exhibiting associations between arsenic exposition and cell types of lung cancer.

LocationNumber of lung cancer casesCell typeSmoking statusCalculated riskDosageReference

Britain6 cases treated with Fowler’s solution or potassium arsenite (2 male/4 female)(i) 5 undifferentiated carcinomas
(ii) 1 SqCC
3 never smokers, 1 smokerNANA[94]

Taiwan(i) 76 LC cases (50 males/36 females)
(ii) 400 controls from the same administrative area
(i) Male cases: 40% SqCC, 38% AdC, 22% others
(ii) Female cases: 19% SqCC, 69% AdC, 11% others
NAOdds ratios for developing LC were 3.39 for whom used well water from arsenic-contaminated zones during 40 or more years,
compared with people who never used such water source
Median of 780 μg/L (artesian wells) and 40 μg/L (in well water)[95]

Japan: Niigata Prefecture(i) 443 individuals exposed to arsenic
(ii) 9 (8 male/1female)
developed lung cancer after exposure to high levels (≥1000 μg/L)
(i) 3 SCC
(ii) 2 SqCC
(iii) 1 SqCC + SCC
All smokers, except for female case for developing LC among individuals ( ) exposed to >1000 μg/L of arsenic in drinking water in a zone contaminated during 5 years in Japan, while individuals exposed to 50−990 μg/L ( ) present a SMR of 2.33[96]

Southwest and northeast Taiwan139 newly diagnosed LC cases from a BFD endemic zone(i) 45% SqCC
(ii) 22% AdC
(i) 31.9% never smokers
(ii) 16.7% past smokers
(iii) 51.4% current smokers
Relative risk according to exposure group
(i) Group 1: 1
(ii) Group 2: 1.09
(iii) Group 3: 2.28
(iv) Group 4: 3.03
(v) Group 5: 3.29
Average arsenic level in groundwater (μg/L)
(i) Group 1: <10
(ii) Group 2: 10–99l
(iii) Group 3: 100–299l
(iv) Group 4: 300–699
(v) Group 5: 700
[97]

TaiwanNational Cancer Registration Program with 37.290 LC patients (26.850 men/10.440 womenMen
(i) 33.6% SqCC
(ii) 19.5% AdC
Women
(i) 29.9% SqCC
(ii) 29.6% SqCC
NAMale and female patients from
the BFD area had higher proportions of SqCC
( in men and in women) and SCC ( , in men, and , in women) but had a lower proportion of AdC
( in men and in women)
(i) Towns in BFD
area: average arsenic level of 0.22 mg/L in well water
(ii) Control towns:
average arsenic
level of 0.02 mg/L
[40]

Bangladesh(i) 3.223 (2811 male) with a primary LC
(ii) 1588 (1183 male) with benign lesions
50.5% and 39.0% of SqCC among smokers and nonsmokers, respectively(i) 79.7% smokers
(ii) 18.5% never
(iii) 1.80% unknown
OR = 1.45,
(95% CI 1.16−1.80)
>100 μg/L[63]

Northeastern Taiwan(i) 8086 residents were followed for 11 years (6888 remained in the final analysis)
(ii) 178 incident LC cases
(i) 75 (42.1%) SqCC
(ii) 51 (28.7%) AdC
(iii) 22 (12.4%) SCC
At enrollment
(i) 59.0% never smokers
(ii) 12.4% past
(iii) 28.6% current
The RRs and 95% CIs for 100–300 and >300 μg arsenic/L when compared with <10 μg arsenic/L were 1.54 (0.97–2.46) and 2.25 (1.43–3.55), respectivelyThe mean (arsenic) among wells with known arsenic concentration was 117.2 μg/L[98]

USA: New Hampshire, Vermont.(i) 223 lung cancer (100 male/123 female)
(ii) 238 controls
75 cases were SqCC and SCCData from cases
(i) 5.4% never smokers
(ii) 94.6% current
Arsenic exposure was associated with SCC and SqCC (OR for toenail arsenic concentration ≥0.114 μg/g versus <0.05 μg/g)Toe nail (arsenic) in 4 levels: <0.05 μg/g, 0.05 to 0.0768 μg/g, 0.768
to <0.1137 μg/g, and ≥0.1137 μg/g
[99]

Data from patients from the Blackfoot Disease area in Taiwan.
SCC: small cell carcinoma; NA: data not available; SMR: standardized mortality rate; OR: odds ratios.