Current Organizations / Institutes

The organizations/institutes from the scholar's latest article

Previous Organizations / Institutes

The organizations / institutes from the scholar's other articles in the past ten years


Chaochen Ma has a total of 32 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Short-term association of air pollution with lung cancer mortality in Osaka, Japan

    by Chaochen Ma, Chau-Ren Jung, Shoji F. Nakayama, Takahiro Tabuchi, Yukiko Nishihama, Haruka Kudo, Toshitaka Morishima, Yuko Ohno, Tomotaka Sobue, Isao Miyashiro


  • Faster surgery initiation in oral cancer patients during the COVID‐19 pandemic in Osaka, Japan

    by Shihoko Koyama, Toshitaka Morishima, Mari Kajiwara Saito, Chaochen Ma, Nao Nishimura, Kengo Aoki, Minako Nishio, Tomoyuki Otsuka, Takahiro Tabuchi, Miki Ishibashi, et al.

    Background: We investigated the impact of the COVID- 19 pandemic on oral cancer (OC), comparing diagnosis and number of pre-operative days in the diagnosis of OC in 2019 (pre-COVID- 19) and that in 2020 (during the COVID- 19 pandemic).Methods: Using data from a cancer registry- based study on the impact of COVID- 19 on cancer care in Osaka (CanReCO), we collected details of sex, age, residential area, cancer site, date of diagnosis, clinical stage at first treatment and number of pre-operative days in OC patients. Results: A total of 1470 OC cases were registered. Incidence of OC before and during COVID- 19 was 814 and 656 cases, respectively. During the first wave of the pandemic (March to May 2020), incidence was about half that in the same period in 2019 (2019; n = 271, 2020; n = 145). Number of pre-operative days (median number of days be-tween the first hospital visit and surgery date) was significantly shorter during the COVID- 19 year (24.5 days) than in the pre-COVID- 19 year (28 days, p = 0.0015).Conclusions: Incidence of OC during the COVID- 19 pandemic was lower than in pre-COVID- 19. Despite disruption in the healthcare system, the number of pre-operative days for OC cases was shorter during the pandemic.


  • The association between dioxins and steroid hormones in general adult males: a cross-sectional study in an e-waste region of China

    by Li Li Shi, Mei Qin Wang, Shoji F. Nakayama, Chau-Ren Jung, Yue Hua Wang, Jing Jian Dong, Chao Chen Ma, Teruhiko Kido, Xian Liang Sun, Hao Feng

    As observed among residents in electronic waste (e-waste) recycling areas, dioxins can disrupt the homeostasis of endocrine hormones and the balance of thyroid hormones. Few studies, however, have examined whether e-waste recycling activities influence steroid hormone equilibrium in the general adult male population. This study evaluated the association between steroid hormones and the physical burdens of dioxins in the general adult male population residing in an e-waste region. In September 2017, 74 adult males residing in an e-waste dismantling region were enrolled in the current study. Approximately 10 mL of blood was collected from each adult male, and the serum samples were separated through centrifugation. Then, the levels of dioxin and steroid hormones in the serum of the participants were measured. We treated dioxin levels as categorical variables in the general linear model according to quartiles (25, 50, and 75 percentile). Comparing the findings with a reference group (< 25th percentile), we noted significantly higher dehydroepiandrosterone (DHEA) level in men with low serum polychlorinated dibenzofuran-toxic equivalent (PCDFs-TEQ) level between 3.80 and 6.31 pg/g lipid (1933 vs. 1447 pg/ml) and low polychlorinated dibenzo-p-dioxins and dibenzofurans-TEQ (PCDD/PCDFs-TEQ) between 8.57 and 15.11 pg/g lipid (1996 vs. 1360 pg/ml). Moreover, a significantly higher androstenedione (A-dione) level was found in men whose serum PCDFs-TEQ ≥ 11.34 pg/g lipd (2404 vs. 1848). What’s more, there were significantly higher 3β-hydroxysteroid dehydrogenase (3β-HSD) concentrations in low- and high-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) groups (1.30–1.67 and ≥ 2.64 pg-TEQ/g lipid, respectively with 719 and 807 vs. 496, respectively). Our findings suggest that specific dioxin exposure may disturb normal DHEA, A-dione levels, and enzyme activity in the general adult male population in an e-waste region of China.


  • Open Access

    Health Risk Assessment and Source Apportionment of Mercury, Lead, Cadmium, Selenium, and Manganese in Japanese Women: An Adjunct Study to the Japan Environment and Children’s Study

    by Chaochen Ma, Miyuki Iwai-Shimada, Nozomi Tatsuta, Kunihiko Nakai, Tomohiko Isobe, Mai Takagi, Yukiko Nishihama, Shoji F. Nakayama

    Toxic element pollution is a serious global health concern that has been attracting considerable research. In this study, we elucidated the major routes of exposure to three toxic elements (mercury, cadmium, and lead) and two essential elements (manganese and selenium) through diet, soil, house dust, and indoor air and assessed the potential health risks from these elements on women from the coastal area of Miyagi prefecture, Japan. Twenty-four-hour duplicate diet, house dust, soil, and indoor air samples were collected from 37 participants. Cd, Pb, Mn, and Se concentrations were measured using inductively coupled plasma mass spectrometry, and Hg concentrations using cold vapor atomic absorption spectrometry. We found that soil and house dust were the primary reservoirs of these elements. Diet contributed most strongly to the daily intake of these elements, with mean values of 0.72, 0.25, 0.054, 47, and 0.94 μg/kg/day for Hg, Cd, Pb, Mn, and Se, respectively. The mean hazard quotient of Hg was 1.53, indicating a high potential health risk from Hg exposure in daily lives. The intakes of other elements were below the tolerable limits. Future studies with a larger sample size are warranted to confirm our findings.