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  1. Fulltext Persistent mosquito fogging can be detrimental to non-target invertebrates in an urban tropical forest
    Lee NSM, Clements GR, Ting ASY, Wong ZH, Yek SH
    PeerJ, 2020;8:e10033.
    PMID: 33062440 DOI: 10.7717/peerj.10033
    Background: Human population growth has led to biodiversity declines in tropical cities. While habitat loss and fragmentation have been the main drivers of urban biodiversity loss, man-made interventions to reduce health risks have also emerged as an unintentional threat. For instance, insecticide fogging to control mosquito populations has become the most common method of preventing the expansion of mosquito-borne diseases such as Dengue. However, the effectiveness of fogging in killing mosquitoes has been called into question. One concern is the unintended effect of insecticide fogging on non-target invertebrates that are crucial for the maintenance of urban ecosystems. Here, we investigate the impacts of fogging on: (1) target invertebrate taxon (Diptera, including mosquitoes); (2) non-target invertebrate taxa; and (3) the foraging behavior of an invertebrate pollinator taxon (Lepidoptera) within an urban tropical forest.

    Methods: We carried out fogging with Pyrethroid insecticide (Detral 2.5 EC) at 10 different sites in a forest situated in the state of Selangor, Peninsular Malaysia. Across the sites, we counted the numbers of knocked-down invertebrates and identified them based on morphology to different taxa. We constructed Bayesian hierarchical Poisson regression models to investigate the effects of fogging on: (1) a target invertebrate taxon (Diptera) 3-h post-fogging; (2) selected non-target invertebrate taxa 3-h post-fogging; and (3) an invertebrate pollinator taxon (Lepidoptera) 24-h post-fogging.

    Results: A total of 1,874 invertebrates from 19 invertebrate orders were knocked down by the fogging treatment across the 10 sites. Furthermore, 72.7% of the invertebrates counted 3-h post-fogging was considered dead. Our regression models showed that given the data and prior information, the probability that fogging had a negative effect on invertebrate taxa 3-h post-fogging was 100%, with reductions to 11% of the pre-fogging count of live individuals for the target invertebrate taxon (Diptera), and between 5% and 58% of the pre-fogging count of live individuals for non-target invertebrate taxa. For the invertebrate pollinator, the probability that fogging had a negative effect 24-h post-fogging was also 100%, with reductions to 53% of the pre-fogging count of live individuals.

    Discussion: Our Bayesian models unequivocally demonstrate that fogging has detrimental effects on one pollinator order and non-target invertebrate orders, especially taxa that have comparatively lower levels of chitinisation. While fogging is effective in killing the target order (Diptera), no mosquitos were found dead in our experiment. In order to maintain urban biodiversity, we recommend that health authorities and the private sector move away from persistent insecticide fogging and to explore alternative measures to control adult mosquito populations.

  2. Radiation Exposure in Patients with Inflammatory Bowel Disease: a Fourteen-Year Review at a Tertiary Care Centre in Malaysia
    Naidu J, Wong Zh, Palaniappan Sh, Ngiu ChS, Yaacob NY, Abdul Hamid H, et al.
    Asian Pac J Cancer Prev, 2017 04 01;18(4):933-939.
    PMID: 28545190
    Background and Aims: Patients with inflammatory bowel disease (IBD) are subjected to a large amount of ionizing
    radiation during the course of their illness. This may increase their risk of malignancy to a greater level than that due
    to the disease itself. In Caucasian patients with Crohn’s disease, this has been well documented and recommendations
    are in place to avoid high radiation imaging protocols. However, there are limited data available on radiation exposure
    in Asian IBD patients.We therefore sought to identify total radiation exposure and any differences between ethnically
    diverse ulcerative colitis (UC) and Crohn’s disease (CD) patients at our centre along with determining factors that may
    contribute to any variation. Methods: The cumulative effective dose (CED) was calculated retrospectively from 2000
    to 2014 using data from our online radiology database and patients’ medical records. Total CED in the IBD population
    was measured. High exposure was defined as a radiation dose of greater than 0.2mSv (equivalent to slightly less than
    ½ a year of background radiation). Results: A total of 112 cases of IBD (36 CD and 76 UC) were reviewed. Our CD
    patients were diagnosed at an earlier age than our UC cases (mean age 26.1 vs 45.7). The total CED in our IBD population
    was 8.53 (95% CI: 4.53-12.52). Patients with CD were exposed to significantly higher radiation compared to those
    with UC. The mean CED was 18.6 (7.30-29.87) and 3.65 (1.74-5.56, p=0.01) for CD and UC patients respectively. 2
    patients were diagnosed as having a malignancy during follow up with respective CED values of 1.76mSv and 10mSv.
    Conclusions: CD patients, particularly those with complicated disease, received a higher frequency of diagnostic
    imaging over a shorter period when compared to UC patients. Usage of low radiation imaging protocols should be
    encouraged in IBD patients to reduce their risk of consequent malignancy.
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